yes, a bug with X-Plane's TPE model for sure...they'll go into reverse eventually, but I've seen it take as long as 10 seconds, quite incorrect. It has been filed and there is some type of fix in the next X-Plane update, which rumor has will be released in a few days; however, until I test it, I'm not sure what the behavior will be. I had a short exchange with Philipp, the programmer of the TPE engine and given the limited exchange, I can't say for sure he understood and/or agreed with how I suggested it be modeled, so I'm not sure what to expect. The reverse should be darn near instantaneous with lever movement...this is due to the way the hydraulic circuit of the 'pitch sleeve' works. I've been waiting on this fix for a bit....fingers crossed. If not, I guarantee I'll be knocking on Laminar's door again.
Philipp has actually done quite a good job of modeling this engine, it worked great in V11, but I believe he added a few more accurate features like NTS lockout etc. and somewhere in the last few patches, reverse in the TPE implementation got broke. I used to custom model this stuff myself, but I've known Philipp for a good many years and he's extremely capable and as Laminar adds more accurate engine behaviors, then the more custom behaviors I have to 'pull out' of my plugin code so they don't clash, but in doing so, I defer to their implementation in some areas. Now having worked with these guys in years past though, they're quite agreeable to suggestions and improvements and I fully expect we'll get this one ironed out.....and I do hope its in this next update from X-Plane.
-tkyler