Here is one more idea to throw in the mix. Just bear with me a bit on this one. Back in '73 in the 1st Arab oil embargo, gas prices doubled overnight, and lots of the hot rod guys wanted smaller cams but ran into the problem the OP is having: too much DCR if they took their high CR engines and put small cams in them to save fuel. So there were a series of cams made back at that time which had pretty short .050" durations and short overlaps and 114 LSA, BUT which had a long slow ramps down to advertised duration so that the intake valve closure was late and bled off enough pressure to get DCR down. Crane had such cams and I bet others did too.
The rollers tend to have fast ramps which is part of what they are good for. Ditto for something like and XE or a VooDoo; those are going the wrong way on ramps. So a slow ramp (below .050") flat tappet would be very good for this.
If there ever was a time for a custom cam, this is it IMHO. This is when I would be picking up the phone and calling someone like Racer Brown and seeing what he could do.
I wish I could run some DCR numbers on this idea and some example cams specs to do this, but it is 'bedtime for bonzo' LOL. Out on the road working long days.....
