The entire issue is their imprinting that can't be easily broken. If young Kwonwoo didn't rope Dowon into it they could've easily gone their own separate ways despite the heartache they'd suffer.
But because they're imprinted, they can't be apart - I guess cuz Kwonwoo can't be guided by anyone else now, or as efficiently. And the center needs Kwonwoo's power, so they're gonna keep Dowon next to him as battery despite the complicated feelings between them. So no, Dowon can't quite leave, also cuz he cares about Kwonwoo, or he wouldn't have risked his life and powers to wake him up.
It's seriously stupid...
Yes, he can. Have you not read the new chapter?
The entire point of being in the hospital taking dangerous medicine was to remove the imprint and they succeded without major sideeffects as well.
They both are free to leave now. And the center wants MC to keep being ML's guide anyway. Without getting ML's memories back. Without letting MC tell him about their relationship. Why? Do they feel pleasure seeing people suffering?! To me, it seems to be the case.
I see the confusion now. ML was not waking up because of insuficient guiding, but because he's imprinted with the MC, the center could do nothing. They were stuck to treating him within MC's limits. MC decided to undo the imprinting (we saw part of the thought proccess in the previous chapter) so ML would be able to get guiding from other people and get better. And here we are.

Dont get me wrong i overall enjoyed this story... but it must be one of the most frustrating stories i ever read. Like author could have come up with other conflicts for their relationship that arent just constant amnesia arc... if i was MC i would just give up at this point.