Here's what I've done so far to create a workflow to edit JamKAT/DITI kits.
(1) I obtained a copy of Windows 10 Education and installed it (via Apple Boot Camp) on my MacBook Pro (OSX Mojave 10.14).
(2) I installed the DITI Visual Editor for PC: http://www.alternatemode.com/downloads/DITI/editor/DITIEDITOR_Editor_Jul_2017.exe
(3) It took me a while (partly because I forgot you often have to install drivers in Windows) to get the DITI Editor to send/receive SysEx to/from the DITI, but I think I have it now (thru a Motu micro lite).
(4) Constantly stare at the JamKAT pad layout and its mapping to DITI inputs.
It's a little clunky. But it's far less clunky than editing via the up/down/left/right arrows on the DITI.