Zelensky gets a peace agreement he will have to content with the radical factions within the country of which there are quite a few.
They are now openly armed.
I don't think the Russians have been negotiating in good faith anyway, and no real negotiations will take place until if and when the coming Russian offensive is defeated.
More likely, after a cease fire or a peace agreement, Ukraine will enjoy a massive inflow of aid from the West and a rebuilding boom that will suppress factionalism.