TinyCLR vs .NETMF for today's embedded app

yes, NETMF 4.3 QFE2 released 3 years ago is still the preferred and recommended for production
TinyCLR OS is still alpha and missing features you seems to require

regarding support, if you find a bug in NETMF you have bad cards to have it solved, if its related to GHI’s code it looks like it depends