I was not referring to anyone in this forum (I don’t remember seeing anyone post about it here, actually), but I’d remembered a few threads in the Macrumors forums. I just did a quick googling and found this recent thread pretty quickly. Apparently the MBP draws more power if you utilize the MBP screen alongside an external monitor than if you use two identically configured external monitors (with the MBP lid closed).
As someone who cannot abide fan noise (as I’ve noted before I chose a 2017 i5 iMac over i7 because the i7 chips were prone to getting the iMac fans going when doing nothing more than scrolling) I’d never go for a laptop setup in which the fan would always be going when in desktop use as described by the OP.
Returns of a 49" 46-lb monitor might be a little more problematic.