Ryzen AI max+ 395 128GB can do 256GBps so lets put all these "ifs" to bed once for all. That is absolutely no brainer to drop more RAM as long as there is enough bits in address space of physical hardware. And there usually is, as same silicons are branded and packaged differently for commercial market and for consumer market. Check up how chinese are doubling 4090s RAM from 24 to 48GB.