Far from expert,more of want to be rookie. I believe you will find that running support from rear to trans or engine if that what you are asking about ,will just cause handling or breakage issues. The design of the drivers compartment will eliminate the flex part. Car has to have some flex to work and chassis from motor plate forward it has plenty. When we ran TA?FC they made rule about diagonals in floor section. We had a very reputable chassis builder install some. Result first DNQ in 4 years for first race,second race we where not NQ 3rd qualifier. Did some thinking. Took porta band and cut the bars with a thong(like tuning fork).Result 4th shot early shut off number 2 qualifier.
HAd cpl friend who bought a TF/FC chassis to run TA/FC. did not work worth crap.Was to stiff for power. Built for 8000 hp and 3000 hp was not enough to make it work. Pretty sure Roo man or Bruce will chime in. and give you lot better info and heck probably tell me I am full off,well you know.LOL