Pronouns, like above mentioned parts of speech, take part in the formation of parenthetic modal components of the utterance. However, their role in this case may be different.

Firstly, the pronouns alone or in combination with other words form parenthetic modal units. This happens, for instance, during modalation of pronouns-adverbs in no way, in this way (in this manner), and the substantivised pronoun- adjective that one in combination with different prepositions. Compare contexts of their proper pronominal (1) and parenthetic modal use (2):

(1)  .. I could in no way stand the thought that Vodopyanov pereulok no longer existed (V. Kataev. My diamond crown) [7] (pronoun-adverb with the meaning 'in no way' in the function of adverbial modifier of measure and degree); In this manner we reached a drying out, impounded small river with a bridge. (A. Solzhenitsyn. Matryona's place (Matrenin Yard) ) [Ibid] (pronoun-adverb with the meaning ‘in this way' functioning as adverbial modifier of manner); Jerome was an haughty man, full of conceit whom I felt nothing, except that involuntary respect, which all grownups impressed on me (Leo Tolstoy. Adolescence) [Ibid] (substantivised demonstrative pronoun as part of dangling complement with the meaning of excepting);

(2) Aksinya looked cautiously towards her husband: "You seem to be going somewhere, don't you?" (M. Sholokhov. Quiet flows the Don) [Ibid] (parenthetic modal word with the meaning of assumption); Well, one day after I spent two hours sitting on a small bench with the surgery department assistant, she respectfully asked me... (Yuriy Dombrovsky. Lady Macbeth) [Ibid] (parenthetic modal word with the meaning of ‘exemplification' used to illustrate the expressed thoughts); The room smelled of perfume, apart from that the smell of hot iron was entering it from somewhere (M. Bulgakov. The Master and Margarita) [Ibid.]; Moreover, the doors of such a shop are usually bedizened with bundles of literary works - popular prints on large sheets... (L. Yuzefovich. The house of assignation) [Ibid] (parenthetic modal expressions with the meaning of addition, attaching).

Our example with in no way / seem (2), demonstrates a functional-semantic type of pronominal modalation, related with the violation of the word semantic identity and the formation of grammatical and lexical homonym, while in example with apart from, moreover (2) there occurs an exceptionally functional type of transposition into the parenthetical modal units, the result of which is the formation of grammatical homonym.

Apparently the prepositional (locative) cases of substantivised demonstrative pronouns that function as anaphor, i.e., reference to the pretext are to a larger degree prone to the process of modalation (such as meanwhile, moreover, apart from that). Compare pronominal (3) and parenthetic modal (4) types of word forms usage:

(3) Beside that guy, there were others...;

(4) Many of his friends went far, moreover, the city higher-ups, managing and standing in line for power, is always in sight... (V. Rasputin. New occupation) [Ibid.];

A special position is occupied by pronouns, formally correlating with adjectives and nouns (apparently, from our point of view, in fact, indeed, by the look of things, probably; nothing, no point): they become in combination with other notional and sometimes relational words part of introductory word collocations (5) and sentences (6):

(5)  ... These results, from our point of view, will bear on the interests of the North American States (V. Rybakov. Gravilyot "Tsesarevich") [ibid.]; Apparently, what was going on was a crushing defeat of the dissenting geneticists (D. Granin. The Bison: A Novel about the Scientist Who Defied Stalin) [Ibid.]; 

(6) Nothing to do, had to confess it all to his mother (D. Mamin-Siberian. Ak-Bozat) [Ibid]; Nothing to say, time was difficult, but at the same time there was something beautiful in it (I. Grekova. Break.Pheasant) [Ibid.].

Secondly, pronouns survive in the structure of elliptic parenthetical structures, formed due to "understating" of the whole introductory sentences (Goes without saying <--  It goes without saying) (7) or the participial / infinitive clauses with parenthetical functions (eg.: between you and me < -- between ourselves ) (8). Cf.:

(7) (a) The winds used to blow, of course, but even my grandmother was not able to recall a such one, and she is still, thank God, alive (Alexander Grin. Willow) [Ibid.];

 (b) He lost his parents when he was a child, and was brought up by Princess Anna Shcherbatova, famous all over Moscow by its quirks and wealth old virgin, whose all thoughts, needless to say, were occupied by our young then hero (E. Radzinsky. Chaadayev) [ibid.];

 (8) (a) This was the noblest, kindest creature, loving and capable of all sacrifices, although I must between us confess, that if I had not had the misfortune to lose it, I would probably not be able to talk to you today... (I. Turgenev. Hamlet of Shtchigri District) [Ibid];

(b) Whatever you would say, but the artillery we have, between us, is remarkable (A. Panteleyev. Anechka) [Ibid].

Thirdly, the pronoun-nouns are subject to ellipsis, reduction during understating of introductory (parenthetical) two-member (9) or one-member (10) sentences (eg.: think <-- I think; imagine <can you imagine; know <-- you know; says <-- he says; seems <-- It seems to me; as remember <-- as I remember). Cf.:

(9) (a) Without criticism, I think, there is no progress (Yuriy Dombrovsky. The Keeper of antiquities) [Ibid.];

(b) Dinner, I think, was a marvel (S. Nosov. Curved brackets) [Ibid.];

(10) (a) For the accuracy of calculations I can not vouch, the real numbers are classified, the Party, I think, still feels being underground... (A. Azolsky. Lopushok) [Ibid.];

(b) He was handsome, there is no denying the truth, but firstly the beauty alone, seems not enough, and secondly, there was something in his appearance... something from Yesenin's picture (V. Belousova. Second shot) [ibid.].

Therefore, the role of pronominal lexis (vocabulary) during the transposition process of modalation, i.e. during formation of parenthetical modal components of the utterance (sentence), which explicate the position of the modus subject, may be different. They can on their own generate parenthetical modal words and expressions, entering into their structure as a grammatically organizing or subordinate component, or, on the contrary, be subject to ellipsis of certain parts of introductory constructions in speech.

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