yeah, it was a long shot... but sometimes the simple things are the things that trip us up.
its a bit odd, if your receiving data, then its obviously connected.
I've checked the LCXL programmers guide, and it says it only has one port, so if its connected for input, then there is no reason output should not work.
when we send data, we basically send 5 things (e.g. note on), midi port, midi channel, note on, note number and velocity. given we do this the same for all devices, and it works, Im confident our 'format' is correct.
Im assuming one of these the LCXL is thinking is wrong , and hence ignoring. (hence my above post, and suggesting trying other ports)
the only thing I can think of at the moment, is trying to send lots of different data to it, to see if anything reacts, if it does, that might give us a clue as to what is happening, and what the LCXL is filtering, or more importantly not.
you can send sysex in custom object using the firmware 'api', see my Push object in the community library (hint: display) . we don't parse incoming sysex
there is no generic object, and I think it would be hard to do one that would be both useful, and not potentially cause performance issues. ( I think max/pd is one of the few music apps I know that allow sysex parsing)