Asking for a friend,
no kidding, @vasyugan may have some kind of a rare usecase, but i figure this would be nice for a lot of people.
The Desktop Client supports multiple accounts, but they get worked on in a sequential manner, so when one account is hit with a large file, the other stalls for the time that file is beeing processed. Imagine, somewone shares an iso or something, so you have to wait for an hour or so to see your 1KB textfiles from the other account to be synced.
See our discussion in the other thread from post #5 onward (could a mod pleas close that topic since its the wrong place, and also the initial OP is already solved):
Also see his Feature request on Github: Feature request: parallel download from multiple accounts · Issue #1508 · nextcloud/desktop · GitHub
I am not a coder, but i have “some” insight into how the client is built, so i feel its very possible to have different processes working on the different accounts in a parellel matter.