Max,
The T4 top piece and bottom piece are they same 8W? Think can squeeze in 3x8W too if you use the pin connector of the PL light instead of the standard one from T4. Can't see your bottom piece T4 light connection, is it using the pin connector wire?
Good mod, and that's what I'm doing yesterday too but still haven't get the pin connectors yet.
Those reflectors are they cut from the existing ones or those sold by Reborn??