What is alacritty's RSS expected to be?

If I open a new terminal and run top, RSS is 54MB, but if I then hold ctrl- (top still running) until min font size is reached, then hit ctrl+ to restore font size, it's 165MB, and faffing about with zoom like this for a couple of minutes brought it to 375MB.

System

OS: Linux Ubuntu 20.04LTS x64
Version: alacritty 0.10.0-dev (62a1fad)
Linux/BSD: X11 dwm