Thanks to all who replied.
I'm in correspondence with CatTrike regarding the crank/wheel overlap. They tell me that they are working on a shorter frame, since they never recommend shortening the boom to the point that the crank would overlap the front wheel. They indicated that they expected to have the shorter frame in a couple of months. I think we'll invest in one at the end of this season and see how it works out for us.
Thanks again,
Fran & Nan