it does not work like that… 8tflop rdna3 is becaue they count the fpu perf like it is done on ampere/ada ie both the int and fpu alu can to fp while older u arch had fixed alu for int and fp.
And there is a problem with the rdna3 where this function is not working correctly so we only get the additional 30% fpu perf from the additional fp alu units.
and like u sait the memory is holding back the apus but it will still not perform like an 8Tflop gpu.
lga1700 cpus are very effecient if you play with the power limits. I 12700k(2x), 12900k and 13900kf and all of them were super fun to see how they performed at lower watts.
I gaming they dont consume much at all, but I do not run with the e cores at all :)