This is probably not closely related but I'm running 1.19.2 (2017-09-01) and noticed that the final line of my tfree macros is not reliably executed (when using the select tool command in the WebUI). It sometimes finishes the macro without performing the last move but will perfectly execute any following command (which ofc could cause a crash into the dock). I ended up with duplicating the final line to safeguard its execution.
Magnetic tool changer on a corexy.
[[language]]
; tfree0.g
; called when tool 0 is freed
;
M83
G0 E-5 F1200
M82
G0 X252 Y215 F16000
G91
G0 Y47
G0 X30 F4000
G0 X4 F2000
G90
G0 Y215 F6000
G0 Y215 F6000