Yes, for now, with this mod, Miria unconditionally joins the player, even over the party limit. That's one of the things I want to change later. But first of all, other fixes and better documentation - should be easier to start during the week-end
The Gauss Rifle is a fantastic weapon for Better Miria to use in the late game. She keeps missing the target more often than the PC and the other NPCs do, but when she doesn't, she makes even the Enclave troops in (Advanced) Power Armor suffer.
While for both Fo1 and Fo2, the games as stupid should be faster than full quest runs, I wouldn't expect them to be real speedruns. Indeed, the player has got to level up somehow in order to be able to survive the fights of the late game - which is even harder as stupid loner, of course (using Mentats to recruit NPCs or do the stealth / smart ways to destroy MB, Cathedral and Enclave is cheating in stupid games ^^).
Granted, when playing as stupid, there's no need to play Fo1 MB, Cathedral or Fo2 SAD (if that can be reached in a stupid game), Navarro, Enclave in hostile mode, since the people at some of these locations aren't going to react negatively to the NPCs...
Some random encounters of the areas of the late game are especially dangerous as well: for instance, (super) mutant patrols in Fo1, Enclave patrols in Fo2, large packs of floaters + centaurs in both. Clearly, the dude and party survived some of those only thanks to their collective armor and firepower. Sometimes, a NPC died; the low HP Tandi, Dogmeat and Miria are certainly more subject to this fate than the other NPCs. Worse, even in the late game of my second Fo2 run with RPU + modified Better Miria, shortly before finishing the quests in SF and going to the Enclave, at level 34 with Bonus Rate of Fire, Sniper and other crucial perks, Advanced Power Armor, the party equipped as described on the previous page, an Enclave patrol with 7 members quickly killed my (not fully healed, but still) dude, and I'm not sure I'd have had even the opportunity to run away from the encounter. Of course, I canceled it by restoring from the previous save point - it probably was beyond the 800th individual save file, at that stage.
I remember reading the TCRF page for Cryo's Dune 1, but given that you mention it takes hours, I guess I'd better not read the TCRF & TvTropes pages for the Fallouts before I have produced a new release of the Better Miria mod
Agreed about Fo1 & Fo2 being significant milestones in the history of computer RPG. Besides, people still spending significant time to mod the games 23-24 years later is another form of testimony to their legendary status.
Dune 1 is a good game too, BTW. Good graphics and music, despite the FDD version being only ~2 MB; I don't like the CD version because orni and worm travel, while pretty, is too slow, and the refreshed visuals are questionable. In pre-Internet times of the mid-1990s, it took me a while to discover how to finish the game on my own. The storyline is basically linear, based on a number of sequence points, but the replay value is elsewhere: for instance, optimizing the travel and combat actions to reduce the in-game time (beyond a point, one needs to take advantage of a game engine bug to go much further on that front), maximizing the amount of mined spice, etc.
The Dune 1 and 2 games from the early 1990s still have some following as well, and a bit of modding activity (especially for Dune 2, which lends itself to modding better) occurs nearly 30 years later, so I guess these two games are legendary as well.