Currently where the active discussions are taking place:
https://www.elitetrader.com/et/threads/on-10-case-geometry-and-beyond.310880/
https://www.elitetrader.com/et/threads/making-jh-sct-and-all-his-material-alive.320588/
I wouldn't get hung up on 'lost material.' Jack spawned a web of posts where by following links and using long-tail search strings, all the pieces are still here/there. It is true as time passes links in google search results are diminishing but for some things adding the time era helps dig up older stuff.
Imho, for the newly exposed, starting at PVT is essential. There are concepts presented in each of his systems that dovetail into each other and without the essential background as one attempts 'short-cuts' the only short-cut is how quickly ones capital gets extracted from you vs extracting capital from Wall st. Starting with a premature entry with an incomplete knowledge base exposes oneself to unnecessary risk.
I believe this was intentional in that money-grubbers just want short-cuts and not really interested in developing their 'spectrum of differentiation.'
Software is awesome yes, and it all starts with doing drills with paper, pencil, 3-ringed binders, a ruby red eraser and working with the software between one's ears.
edit: I think what trips up some folks is reading to 'get through' a thread vs reading for comprehension. With that said, I'm gonna focus my replies to this thread as it specifically relates to software and leave the other discussions for other threads.