I didn't like the thin unsupported nature of the belly skin in the tail cone either. I noticed it when adding an ADF antenna behind the elevator bellcrank.
O.K., so I'm weird for ADF..

But that fuse bay is stiffer due to the antenna doubler. The farther aft you go, the smaller the unsupported area.
You could rivet in some light angle such as the skin stiffeners in the elevator?
I messed up one elevator skin, so I had some spare stiffeners around. They turned out to be useful for all manner of small things.
Keep the weight down.
__________________
Scott Emery
http://gallery.eaa326.org/v/members/semery/
EAA 668340, chapter 326 & IAC chapter 67
RV-8 N89SE first flight 12/26/2013
Yak55M, and the wife has an RV-4
There is
nothing-absolute nothing-half so much worth doing as simply messing around with
Aeroplanes
(with apologies to Ratty)
2019