I bought a new laptop with 16 GB of DDR5 (8 GB soldered and 8 GB socketed) as it was super cheap for an 8840HS, and was planning to buy a 48 GB SODIMM for 120€ but held off on it for multiple reasons, thinking "it can wait and I can make do with less memory for now"
Yeah that 48 GB stick now costs 500€ which is just 50€ short of the entire laptop...
I highly doubt it's going to need a supply that can do at least 9V to exit shipping mode, at least I haven't yet seen a device behave like that. I more so think that's what power supplies Valve suggests to use if you want to play and charge simultaneously, that being said I believe actual power usage is going to be somewhere around those 27W at max so the battery doesn't discharge, with 45W being a buffer to charge the battery while in use, though that's still just a wild guess.