jmcgrogan2,
Your MC-0.5 experience mirrors mine so I understand your conclusion EXCEPT I have an additional chapter.
2 MC-0.5, sounds good but tight so moved to HT system. Like you, I'm very busy and can't listen daily plus all tube system with 8 power tubes per mono, so like to avoid use for break-in.
Learn from thread dark and hard are expected but will open up after further break-in. After ~5 weeks, moved back to main, sound improved, no longer dark or hard but slightly too agressive. I guess the best way to describe MC-0.5 is like going from a regular to HD TV. In this case, it was HD X-RAY TV sometimes.
Had to ship preamp to VAC for upgrade so system was down for 7 weeks. Moved MC-0.5 back to HT. After getting preamp back and break-in, tried MC-0.5 again in main and this time it was regular to HD TV, no more HD X-RAY. The only difference is upgraded preamp and replaced 7 SR RED with SR BLACKS fuses. (The most obvious differences between SR RED and BLACKS, BLACK is more organic with improved PRAT.)
Listened for 6 hours and next concern was SQ following day ... back to dark and hard again?? To my surprise, sound was more relaxed. It's like moving a cable and now had time to settle. MC-0.5s in system for a week now and still sounds great.
Since your MC-0.5 are broken-in and no longer dark or hard, I don't have any suggestions. Like every tweak or component change, it's a fine line whether it works or fails.