Sgian - very strange. Everything in main.cfg looks okay. Are you noticing the fatigue actually increase while you're at 512x? If you're just gaining small amounts of fatigue over time, it could be because RadioReport=8, meaning you'll be picking up fatigue every time you get a message. Of course, that still doesn't seem like it'd be enough to force you to return home.
RUb 1x would "resolve" the problem, sort of. As you've probably figured out, the 1x mod can be used at higher TC's as long as you up the 3DRender= value to something higher than you'd actually use in-game (e.g., I set mine to 2048). However, with RUb 1x your crew does become fatigued excessively quickly - I wouldn't try any Drumbeat patrols with it. Kaa's works on the same principle, but allows for longer patrols.
Sgian and JonZac - If you're looking for Kaa's fatigue, I'm not sure you'll be able to find it in an immediately usable format. IIRC, it was originally released for an older version of SH3 Commander, which used a different format for fatigue mods. One I get home tonight I can post a version that works correctly with the newest edition of SH3 Commander.
As to combining NYGM and other fatigue mods, I simply pasted the morale sections of NYGM into the Kaa mod in the SH3 Commander fatigue file. AFAIK the NYGM/Kaa hybid works, but it needs some more testing to confirm that there aren't any strange side-effects.
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