I do not have the belly board on my plane. There appear to be two schools of thought as it pertains to them. Can't live without it, don't know what its like to have one. The only person I know that has one on a TriQ and does not use it is Lynn French. I would hope he would chime in here. Others have them and use them. Not much help, but maybe we can get some conversation going that might help you.
TriQ 200 N7868B 197 hrs
Now the question I have for you as a fellow Tri Q operator, have you got the speed brake fitted, and if so where is your handle placed ?
I have both Throttle and Mixture controls on left hand lower panel ( sub panel beneath the bolt on part ) and just tried the speed brake handle behind there, but it seems quite tight.
As always your advice is very welcome.