Tacx flux not compatible with long cage deraillers?

So I ordered a tacx flux. After I ordered it I realized it isn’t compatible with long cage deraillers and I just got a new speed concept with what appears to be a bit longer than normal derailleur. It’s the Ultegra 8050 di2 rear derailler. Is this considered a long cage derailleur?

Long-cage is typical with MTB derailleurs and triple ring cranksets. (think big range between low and high gear)

Ultegra DI2 only comes in a ‘medium’ or ‘short’ cage, so you should be just fine.

Ok thanks for the reply
.