I picked one of these up as well. Thanks for posting the GRBL update.
Here’s the settings I ended up on to get all the soft limits and homing working properly.
GRBL 1.1f Settings
$0=6
$1=255
$2=0
$3=3
$4=1
$5=1
$6=0
$10=1
$11=0.010
$12=0.002
$13=0
$20=1
$21=0
$22=1
$23=3
$24=600.000
$25=3000.000
$26=250
$27=1.000
$30=1000
$31=0
$32=1
$100=80.000
$101=80.000
$102=80.000
$110=9000.000
$111=9000.000
$112=9000.000
$120=1000.000
$121=1000.000
$122=1000.000
$130=220.000
$131=280.000
$132=1.000