Although the tank is now done (if you're on Facebook), I will go through the thought process in tackling the problem.
First, a bit of discussion about the two variants (correct me if I am wrong as I am typing off memory) - the 2A6 is an improvement upon the basic 2A4, where it retains the basic turret structure while addressing a number of weak points of the older tank. This includes adding additional armour around the crew spaces, resulting in the arrowhead turret cheek profiles containing spaced armour, and swing-out front side quarters. The front of the lower hull similarly gets added armour plates, with the driver's hatch being changed from a swing-type to a slide-type. A known weak spot, the targeting optics, which were recessed in the 2A4, have been moved to a pod that sits proud of the turret top deck. Side skirt configurations were also changed - while I know the 2A4 uses heavy rubber side skirts, I am not sure but suspect they changed over to steel plates.
All this is great for the 1:1 tank, but when it came to the 1:16th scale tank, I was faced with a problem. Tamiya designed their 2A6 as a 2A6, and did not take into account the tank's internal dimensions. As a result electronics, wiring, and components used up the entire internal volume of the model - not good news if you need to make all that fit within a smaller space. I quickly figured out what space I would be losing:
In a nutshell, the T-07 DMD/MFU needed to be moved - the wiring for the motor cables and the gun barrel strobe unit needed someplace to go; in a normal 2A6, this was already a challenging task to manage nicely without the dreaded turret sag. Even the optical instruments droping into the turret spaces was critical. With much less volume, it was looking quite impossible!
To be honest, when I started cutting into the turret, I didn't have much of a game plan, except that I might have had to relocate major components into the lower hull by sacrificing the speaker box. Sometimes, instead of planning, you just needed to take that first step!