So far, the "mod" is working fine for me. I have to use the original auto-save at the end of every session, dismiss all companions at camp before a long rest, fast travel back to camp to reacquire them after long rest, and only load the original auto-save if I have more than a 4 person party at the time; but whatever ...
Main Character: Criminal, Custom Drow, Divine Soul Sorcerer. Custom Companion: Outlander, Custom Lineage (Human), Hunter STRanger. Custom Companion: Folk Hero, Wood Elf, Land Druid (Artic). Origin Companions: Shadowheart, Lae'zel (Battlemaster), and Wyll.
Wow. I don't need to do all that. Once I modded a save, I play the game, save like normal, dismiss no one, and I'm fine... Except for the above mentioned game crashes. Lol.
I've made it work on original save as well as ones I had way into the game. The only one it won't work with is my party of 4 custom characters.
Either way, it's a pain. It would be 1,000 times better to NOT have to mod.