Does it make sense to remove the left hotend if only prints on the right hotend are needed?
It should reduce the weight in theory. Is a recalibration needed?
Till
From a purely technical standpoint - yes - removing a few grams would make it a fraction of a percent faster. Would you notice? Probably not.
Honestly I’m not sure if the printer will allow you to start a print with a nozzle missing [I’ve never tried]. I know the SnapMaker U1 won’t run if one of the toolheads is damaged or disabled so anecdotally that kind of experience does exist in the 3D printing world.
You would need to update the print speed in the settings to see any improvement. You can also do this without removing the hotend if you want but you may see increases of VFAs. The H2S does have slightly higher settings for movement speed, but the part you can remove from the H2S is only a fraction of the extra weight compared to the H2S.
If you want to actually print faster, I suggest a high flow hotend and higher layer heights and print widths.