Do the adjustments from UBL get applied only during a print? Or do they apply during move commands also?

I'm about to move to 1.1.8 from 1.1.4 and I'm going to give UBL a shot but I'm curious: do the mesh adjustments apply during normal moves, or only during prints?

For example - what if based on my mesh that X50 Y50 needed a Z compensation of -0.05
If I manually sent G1 X50 Y50 F2400 then G1 Z0 F1200 would my nozzle actually end up at a true Z0 (so, compensated) or would it be at +0.05 (no compensation)?

That is the wrong perspective. If UBL is active... The Z-Height correction is happening. If UBL is not active... you are operating in machine coordinates.
A simple example would be G26. You can run the Mesh Validation Pattern with UBL active or not active. In most cases, it makes sense to run it with UBL active.
The reason is... It is commonly used to see how well your mesh reflects the reality of the bed and the machine's deviations.

But... If you want... You can run G26 with UBL not active and see what areas of the bed you will have problems using without any bed leveling active.

Hey Roxy - thanks for the response!
That makes sense! So if UBL is set to active (G29 A), then will it compensate globally after that point? (so if I jog my X axis, it will compensate) Is that correct?

Yes... You can use the UBL G29 Q option to load different (dramatic) test patterns as the mesh. That makes it easier to play around and see how things behave.
Do a G29 Q1 T and look at the created mesh. Then move your nozzle to the center of the bed and jog it 100 mm either way... With UBL active, you will see the nozzle rise as it crosses the line.

Thanks! I'll give that a shot - I can't wait to get UBL enabled on my printer. It looks amazing!