Jonno said:
They're on the Dr Gonzo laserdisc transfers (maybe others too - Editdroid?) IIRC they're fairly intermittent, rather than wall-to-wall observations, but I suppose commentaries weren't all that common in 1993 and the potential had yet to be fully realised.
I agree that after-the-fact commentaries are generally best, as are those recorded 'live' with one participant or a small group (I'm not sure who these cut 'n' paste jobs are supposed to impress - as someone already mentioned, it's not as if we haven't heard it all before).
Criterion had been doing commentary tracks for several years by 1993. (They invented the idea!) If they couldn't get someone who was still living, they got the best historian to discuss a particular film. In the case of Robinson Crusoe on Mars, they made good use of an interview the late director had given in the 1970's. His remarks were synched up to relevant scenes.
The "Definitive Collection" was rightly razzed for the long gaps of nothing and not getting remarks from key personnel no longer working at ILM. Not to mention some of the worst packaging in the history of the Laserdisc format. ;)