As I was about gluing the tail part of the plane I spend some time trying to stiff a tail part to remove wobbling effect. I end up with two conclusions:
1. Tail part is open from aft part what is making whole section flexible
2. Horizontal stab miss one line of stiffening; actually it is so soft that plating is deflecting inside by itself.
Following this opinion I have worked some medicines:
Re.1 I printed tail part with 2 layers bottom plate which after printing went through whole cutting, I guess part can be modified as well. My solution does not require it
Re2. I have modified horizontal stab introducing additional line of elements; weight difference is little less than 1g
If someone is interested I can upload modified part to thingiverse and share with you.
I am concerned about all the section joints where they glue to one another i think it needs to have all the fuse strengthened with a spar of some sort i am worried it will come apart in the air with the strong wind where i fly