Ummm, interesting
I have actually gone the other way and reduced my payload by about 8Kgs. You have set both the Canon Lens and the ED80 down low so that should be a help, so long as your balance is fine, and by this I mean in 3 axis, you should not have too much of a problem.
The G-11 is rated for 60lbs which, I consider to be conservative, and you are mounted on a solid and substantial pier, that with the Maxxon motors I think you should be OK, but, balance is critical.
Cheers
JohnG