I'm more then A little color blind so I do some drastic things to the bottom of my planes sometimes, I love the checks, I think I could see them in the dark.
Have you ever tried an exhaust deflector?? I had to put one on my trainer because my students were getting burnt out cleaning the nitro snot off it. I made A nice bead around the muffler pipe with some JB weld and it has stayed on very well with the fiber ties.
RCER, are you sure it's A weak tail section??