when I was playing precision with a diamond as short as one (so we didn't have the precision 2D bid based on solely short diamonds), it just made auctions relatively clumsy. A way around this that we decided upon was having 2D being miniroman, showing all hands, 11-15 with 4-4-0-5 if the 5 card suit is a minor and all 4-4-4-1 hands with any singleton. I'd never used this convention before, but it had the beautiful side effect of 1D, 1H, 1S, and 2C promising 5+ cards in the suit opened. I quickly started to adore the convention in this context due to being able to bid as if the suit opened was a major suit. Since this addition, I must agree the 2C opener seems to be the most difficult in the system to deal with. As such, I almost always just hope to not have to open 2C, opening 1NT if i'm 5-4-2-2, so only opening 2C if I have a 6th club or have a singleton.