It's that time of the week, where I spew forth more of my "God... it'd sure be great if: SP had this | SP did this | ...etc"

TL;DR -
1) Make parts not consume fuel when their power or powerMultiplier is set to anything <=0
2) A part that is JUST the Nozzle section off the BFE150; can either be an engine that produces thrust ala the T1000 prop hub, or a decoration part that just provides the response to Input and its Exhaust output
3) Make the modeled V-12 attached to the Engine-Prop-2 into a standalone model; ideally as a functioning part that Wheels can be powered by, like Car-Engine-1, or simply a non-functional decoration part, but either way if possible it should at least have paintable valve covers.
4) The old NoseCone-1 is cool! If it was able to have it's rear mating surface be swappable between Circular, Curved, Smooth, Hard, and Custom then it'd once again be a useble part
5) Mix-And-Match between sections of the various Jets. BFE300 fan scaled down to fit a J15, or attaching the BFE150 nozzle onto the J90, etc etc

#1 No means NO!

There are times when we like to use parts for decoration purposes only, and so when it comes to the Engines (Prop or Jet), that means setting their power or powerMultiplier to 0 in order to prevent them from making thrust. That gives us the model AND it still animates -- well, the Prop needs like 0.1 so it at least responds to throttle, but I digress....

Problem is, the engines STILL consume the same amount of fuel as they would if set to 1...
I took the time to test all Jets (not Props) with their Multiplier set to 0 and with a stock Fuel Tank part (20gal), every one of them used it at the exact same rate as though they were making thrust.
(And, no, using a low max Input value won't suffice, since the exhaust-producing jets then fail to have any meaningful visual effect; BFE150 is a prime example)

Use Case: A Harrier jet... It has a massive ducted fan, and so the BFE300, pancaked to a scale of 1,1,0.25 makes a great visual replacement for that (given that the VTOL Engine in SP isn't animated, even if we wanted to use it)

#2 I'd Like the Rump Roast, Please

Speaking of visuals... Sometimes, pancaking the engine doesn't work out great for what we're wanting to achieve, and the space we have to do it in is too small to use the full model...

Ergo, having JUST the Nozzle off the BFE150, as its own part, would be great for compact (futuristic) purposes.
Three ways to implement I can think of:
- It could be similar to the T1000 Prop hub, by being a functional engine as well,
- A "Gizmo", but still has Exhaust Scale effect
- The BFE150 get a new XML/Part setting that hides the "Cowling", which would be the entire engine assembly, similar to how the T2000 is setup now. (Most ideal)

#3 That a V12 in your pocket, or you just happy to see me?

That old Engine-Prop-2 has the coolest modeled V-12, but it's attached firmly to a rather useless motor! :(

OPTION A: Make that a placeable Block (no pun intended) that we can use for decoration. Drag calculations are optional, but I doubt anyone would mind if they lacked it.
[NOTE: I figure it's best it be a standalone part, instead of us simply hiding the cowling+prop, due to the fact the engine seems to no abide by powerMultiplier values, thereby seems it'd need more work be done than worth.]
OPTION B: Make it an actual Engine part that can power stuff! Same as the current.... I4, U8, W8, whatever type it is that Engine is supposed to represent... hahah

I mentioned in another thread that it'd be nice for things like Car/Truck, Tank, or Ship builds. Having size Part Settings would be nice, but we can use scale if nothing else. Though it'd be nice to have at least the valve covers be paintable separately from the engine (ideally, block, heads, valve covers, maybe also whatever that little pipe is on the front of it).

#4 We Leave No One Behind!

Speaking of old parts going unused... That NoseCone-1 is also a shame it's not getting used! I don't know how possible it is, but if, at the very least, the ability to change it's Rear Shape could be implemented (ie Circular, Curved, Smooth, Hard, Custom),

I think that would be a really nice part to have! I really like the look of it, and its only real shortcoming is the fact it can't have its mating surface changed. Granted, the resizability of NoseCone-3 would, admittedly, be handy... but again, we can make due with scale if nothing else.

For that matter, if there are any other Engine Models for Jet or Prop that are in the "Cut Content" bin, but not actually in the game... Adding them as either non-functional models for us to use as decoration, would be welcomed.
(ie if Engine-Jet-3 had a different model than any that are in game)

#5 Build-A-Bear!

5 seems like a nice number to leave off on...
A "custom" Jet engine, of sorts, that lets us mix and match bits from the various engines!

J15 body with a BFE150 Nozzle?
J90 body, with the BFE300 fan on the front, and the BFE150 Nozzle?
VTOL body, with the functional J90 "fan"/grille?
J50 body with the BFE300 exhaust tip/bell/thingy?
"Make it however you like, here at _Build-a-Jet_, net store open at Jundroo Plaza Mall, just off Interstate 11, by the food court!"

Buh-buh-badee-badee-dee THAT'S ALL, FOLKS!