I totally agree that some LW planes have a very hard time at alt. 99% of the time that's where I am, sucking air in a dora that can't fly level at 30k. My group this time ran into MORE than a few 109G14s and K4s that appeared to come in from 35k with ease. Last frame 109Ks over 30K decimated an entire P-47 strike package (2, possibly 3 entire squadrons of us).
However, the Ta152 was really a blip on the radar as far as plane development goes. Only one gruppe (12 planes) was officially assigned to fly them. Over 70 were built, but they never got from the production parking lots to the front line units what with the end-of-war chaos and all.
Let's put it this way: 10x more P-47Ms were flown (officially) than Ta152s. We don't have them in here, do we? For good reason, they weren't really part of the setup.
If you really want more high-alt planes, petition for a greater percentage of 109Ks, less G14s, to represent the G6/AS's, the G-10s, the G-14/AS's that would all have had higher-alt capabilities. They would be far more representative.