best Xcode version for Mojave?

[Richard L. Hamilton]

"On macOS 10.14, iTerm2 @3.4.19 requires Xcode 11.0 or later but you have Xcode 
10.3."

11.3.1 is the newest Xcode for Mojave.

Is there any known downside to Xcode 11.3.1 on Mojave rather than the 10.3 I 
have on there now? Space is tight, so I'm not sure I want both.

And will I need 11.3.1 command line tools too?