As I said, I don't think this is distinct enough from Ironman, nor does it address the 'debug save' issue. Saving once per day is even closer to ironman than the previous idea. But ultimately it's not me who you have to convince.
The problem with auto-saves
only is that the player (deliberately) has little control over
when to save, so these are still quite hard to use for debugging. It's not so much about keeping a hundred saves, but rather being able to save when necessary, and without worry that the game will overwrite that save.
Also, TIL who to blame for the annoying only-auto-names-for-my-saves 'feature' in some modern games.
For me, ESC-click-click-type2-or-3-numbers-click isn't particularly taxing, and saves without description are annoyingly hard to sift through in the case I actually do want to reload to a certain point. But I see no big problem with auto-naming the save after e.g. the in-game date. Make a separate feature suggestion topic and I'm sure the developers will listen, or at least explain why it's a bad idea. I imagine the current state of affairs is so because OXC was a more or less faithful recreation of the original, with some bugfixes, blackjack and hookers added later on. And none of the people who play these old games are particularly bothered by naming their saves, since this is what we've done all our lives.
Multi-slot auto-save seems to be Battlescape only, sadly. I play with autosave off, since it consumes not entirely trivial amounts of time, so initially thought multiple slots covered both Geo- and Battlescape.
Frequency is only for Battlescape.
Unlimited one-keypress save/load is quicksave. Again, I think your needs would be realistically covered by quicksave and a larger amount of Geoscape autosaves rather than anything more complicated.
After playing a whole lot of OXCE, with some big mods, I don't think redoing a week is much of a difference in meaningful paths taken in any but the most pivotal of moments. I'd rather see what the next week has to offer than replay the last one. The mods are long enough as they are.
OXC ironman (and ironman in general) is not popular for its lack of freedom, but rather for the permanence of the decisions. Which means each choice is weighed much more carefully, and in X-Com in particular that there are fewer superheroes and more casualties. The lack of viability/freedom is more of a side effect.
As Meridian (one of the OXCE devs) said, "...everything is possible... the question is if you can do it and if it is worth it". I am not an OXCE developer, just a nosy forumite. But broadly agree with the statement, and even if I didn't, successful forks of OXC(E) are few and far between. If OXCE devs don't bite, you can try asking
Xilmi. But nothing is ever guaranteed.