I messed up with my MRs, and merged them too soon. Multiple constraints in config is fine.
Tcl data has some issues, see https://git.phyks.me/Phyks/flatisfy/merge_requests/6.
See https://git.phyks.me/Phyks/flatisfy/merge_requests/6 and https://git.phyks.me/Phyks/flatisfy/merge_requests/7.