So I was going to make two separate threads, but decided to toss both adjustments into one to add more difficulty and reduce it. Share your ideas if you want.
So first, as far as more difficulty goes, what about map-specific increases in challenge instead of just brutal+ (mutators should be a separate modifier you can apply to any difficulty in my opinion)? For instance, on the miner evacuation map, a difficult setting above vanilla brutal could make shuttles take x4 damage or something, forcing you to really be on your toes about keeping enemies away. Not a global difficulty adjustment that might mess with commander balance, but something that makes you pay attention more. Things like that would make the unique aspects of each map stand out more, I think.
Another one might be for Part and Parcel, where the hybrid uses all of its abilities even when the first one is freed, or maybe just uses them more frequently, so you can’t just lazily kill it on autopilot while macroing.
For Oblivion Express and the shuttle map, maybe a higher difficulty setting removes the safety net of being able to let some escape, or they could move faster, thus making you hit them earlier than you might normally just to make sure you give yourself enough time to finish the job.
As far as something that reduces difficulty and makes Vermillion Problem less annoying to play, why not an “overtime” timer when you hit 0 seconds while a worker is currently carrying a crystal? 15-20 seconds or so. Losing when you’re 5 seconds away from the objective just makes that map so obnoxious.