I remain convinced that Bhadriraju Krishnamurti's version of Proto-Dravidian is one such example of this laryngeal abuse at work, and it seems to me that this can be quickly resolved by examining what a mess he makes out of the pronominal system of this language. As far as I'm concerned it's supposed to look like this (i.e. how most Dravidianists reconstruct it):
|*yām / *nām|
(obl. *yam- /*nam-)
However, Krishnamurti has proposed the following:
|1p||*yaHn||*yaHm / *ñaHm|
He then suggests that the laryngeals disappear in oblique forms. However the process by which this happens is obscure and left unexplained. In contrast, the idea that long vowels are reduced when used in oblique cases or when preposed to another noun is natural and commonplace. For example, we may take note of French moi "me" versus enclitic m(e) "me, myself", the latter being preposed to verbs as the object (e.g. Elles m'aident. "They help me."; Vous me dérangez "You disturb me."). Since we know where French comes from (i.e. Latin, of course!), we know how absurd and off-track it would be to reconstruct Proto-Latin **me(H) "me" in ignorance of attested Latin, placing a laryngeal in there that appears and disappears conveniently like the Cheshire Cat without rhyme or reason.
I have to say that I just don't buy Krishnamurti's reworking of the pronominal system. Whether Dravidian ultimately has a few laryngeals lurking about is, to be fair, a seperate issue that may still hold true, but these pronouns surely don't contain any. To add them here makes analysis more difficult rather than less.
 Krishnamurti, Comparative Dravidian Linguistics (2001), p.336 (see link).