Give 0.5 a try,
http://www-dev.cockos.com/oscii-bot/
Untested, but it might work!
The docs are updated, but to summarize:
Receiving SysEx: @midimsg, msg1/msg2/msg3 will be 0, oscstr will be set to the SysEx data (oscstr will be -1 if it's not a sysex)
Sending SysEx: use midisend_str(device,#sysexdata_as_string);
String reference:
https://www.reaper.fm/sdk/js/strings...s_string_funcs useful functions for accessing binary strings include str_getchar() and str_setchar().
There's no point in doing Lua support, IMO, one easily could port it, but with great tedium.