Here are a few thing with 5.19r4...
Set part zeros - laser - laser on F7 will turn the laser on, but does not turn it off. After a few pokes, it does nothing at all until you hit escape and come back.
With the addition of the USB-BOB to the diagnostics screen, there's a very noticeable delay in the LED state change. This could be misleading to anyone checking their I/O, as it's close to a 2 second delay (on mine at least). There's a bit of delay normally, but once the USB-BOB is enabled, it's twice as long of a delay and misleading when checking I/O.
Up-voting for this again

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viewtopic.php?p=90543#p90543
Sort of related, the new default macro for the GOTO WCS XY0 button (goto_part_xy_zero.cnc) doesn't use the M25 (or G53 Z0 ) as it did previously using mfunc56.mac. This could be an issue for anyone that was used to the old way and hit that button expecting the previous normal motion, and instead gets.....rapid XY, crash, and break tool on material, jig, or clamp!
