Not sure why maximum RAM is so important to you, but the amount of RAM is hardly a limiting factor for normal computing needs these days and has been for a while now. 16GB is more than enough and 32GB is overkill, unless the laptop is used for specific tasks like CAD design or video editing. Even gaming doesn't require 32 gigs of RAM. RAM timings and latency are actually quite more beneficial, and even then the gains are very small.
Having said that, I can't imagine a half decent laptop not being able to support 32GB of RAM, unless one is looking at the very cheap models, in which case RAM would be the least of my worries. The only concern to me would be if the RAM is soldered on to the motherboard or not, but realistically speaking, if you get 32GB of RAM, that will be enough for the life cycle of a laptop, so weather it is soldered on or not would not matter to me.