Alright, here's a few things I can tell you guys.
Before switching off of version 3.1.3 I ran a few more raids of customs and reserve looking for Reshala and Glukhar with freecam and thermal vision to see if they were spawning.
Reshala actually ended up spawning one time with all of his guards - however Glukhar was always solo.
I think this may be a result of SWAG *sometimes* spawning the boss wave and Donut's also only *sometimes* being in charge of spawning the boss wave.
It's a shame because the way I had the mod configured was perfect. The scav and PMC spawns were just right, they were showing up in unexpected and varied places. All of the specific Donut's presets were working as they were supposed to (morescavs, quietraids, etc.) The only issue remaining was the fact that boss guards weren't spawning.
So I downloaded the 3.1.4 Beta version as you asked and only modified the boss spawn chances in SWAG to 100 to begin testing (using only the live-like Donut's preset to reduce variables). This time around, I could not get Reshala or Glukhar to spawn at all until I turned the "UseDefaultSpawns" "Bosses" option to 'true'. After turning on that option, Reshala spawned with all of his guards yet Glukhar did not spawn at all.
(Note: I also set the bot cap to 60 in Customs and Reserve while testing these spawns)
(Note 2: The config that comes with 3.1.4 has Sanitar's spawn chance on Shoreline set to 0 by default)
As a user, it's very unclear what SWAG is doing and what Donut's is doing, and how much overlap there is. Even after reading through the .txt files and the mod page. I understand that Donut's is supposed to be handling the general spawns such as PMCs and scav, while SWAG is supposed to be handling the bosses and special AI groups - but in practice it seems that there's something wonky going on with the SWAG settings just not working properly.
I really want to help get to the bottom of this because this is an awesome mod. Previously I used MOAR for all of my AI configuration needs, but SWAG + Donut's makes raids feel way more dynamic and live-like with the bots being a threat instead of constantly in predictable locations and easy to deal with.
There needs to be a clear way to stop Donut's from touching the boss spawns entirely, while keeping its functionality regarding the scavs and PMCs intact. As it stands, the user experience is misleading because config settings seem to just not work consistently.
I hope you guys can get to the bottoms of all this. I'll keep investigating on my own, it just takes a long time because I'm constantly restarting the game to test new configurations. What I'll do next is try to mirror the configs in 3.1.4 as much as I can to what I had on 3.1.3, and just run tons of raids to see how the bosses are spawning.