I can confirm that the exhaust effects dont show up.
I downloaded the stableversion few weeks ago and had a spin with the trainer p-51 a first.on engine start up you get the initial flameburst when the engine comes to life and
then the smaller exhaust flames when in flight.
even huge flame outs when you keep the primer pushed or mess around with the start sequence.
this doesnt really show up on the p-51. on the trainer version its gone since the update aswell.