This may have been the same on the Longboard, but that was removed mere hours ago so I’ll ask here

With all the testing I’ve been doing for post-install issues, I set my Rapid movement rate to 5500 mm/min to match the default max rates for X and Y. X only or Y only jogging movements match the speed of g0 commands, but diagonal X&Y jogging is visibly slower for both axes as well as being slower than g0 diagonal commands (ex. g0x100y100).

Is this by design, or is there some setting I’ve missed this whole time?

The X and Y axis should both move slower in a diagonal move than a move on one axis alone to achieve the same speed at the router. Lets take a 45 degree angle move for example because it makes the math a little easier. The pythagorean theorem states that A^{2} + B^{2} = C^{2} where A and B are the legs of a right triangle and C is the hypotenuse. So if you move 1 unit to the right and 1 unit to the back the diagonal is √2 or 1.4142135624. The other way to look at it is to move one unit in diagonal at 45 degrees you need to move √0.5 or 0.7071067812 on each leg. That tells us that both the X and Y are moving at ~70% speed to get 100% speed along the diagonal.

Maybe you already knew all that but I thought it was worth mentioning.

I’m not sure why jogging would be slower than g0 though.

EDIT: Thinking about the second part some more and I bet that g0 moves each axis at the maximum speed whereas the jogging command moves the router at that speed. That would mean g0 is ~41% faster than jogging for a 45 degree move.