I'm almost done with the turret. 80% of the parts that go on are unneeded and to not support the armor - just in case anyone building this kit wants to save some time. The only critical parts are the rails to hold the turret armor and the two disks per side to hold the forward rail. This is the turret ready for the MEXAS armor:


Check steps 28 and 30
of the instructions to see what I mean.
With the armor on:

the right rear armor section is still sticking out a bit - I'll have to re-do it. It seems to be a common issue with this kit - I've seen some online builds with that block sticking out a bit.
One oddity in the instructions is step 32, where you have to add the shield between the rear of the armor and the bustle rack. It calls for two parts "M1" and "M2". M2 is just the matching left side or part C16 (step 33) but I haven't found the "M1" part, anywhere on the sprues so far. If I do find it, it's easy to tuck it in behind the shield.
I mounted the gun barrel temporarily and I think it needs a sleeve to thicken the base of the barrel as it goes into the mantlet armor:

