Any experience on this? Is pure craziness?

Throw on advanced sensors and push the limit and you'll move wherever you want.

Then you'l die the next turn.

I don't think anyone is brave enough to not use Advanced Cloaking Device or the Particle Accelerator.

Your better of running 4 sigmas than trying to boost with them. If you to try unorthadox phantoms hull upgrade makes a 28 pt x wing, which isn't terrible. Just doesn't really fit in a list anywhere that turr or soontir wouldn't do better

It really depends on what you're trying to accomplish, but it's probably crazy. The one thing I see that Engine Upgrade would do is let you play more conservatively when trying to catch an Outrider with a HLC, being able to boost into a safe range if your initial movement was too short. Any other situation, though, and you're giving up too much to be able to have that boost.

The great thing about the Stygium Particle Accelerator and the Advanced Cloaking Device is that they both add to the action economy of the Phantom, giving them a free defensive action just about every turn that won't stress them out or limit their maneuverability. Engine Upgrade, on the other hand, would prevent you from using either of those modifications, and your only way to get extra actions would be a free focus from Whisper landing a hit or by using Push the Limit (which really hampers the maneuvering options of the ship on subsequent turns, a certifiable "bad thing to do").

You'd be running them as ultimate glass cannons, taking them for their attack dice.

You could run 3 sigma's with EU, tactician and FCS but I would advise against that. But try running one as a striker. Cloak first, stay cloaked until you can get in there and open with five dice.

I have thrown together a list that has

Echo + PTL + EU + Adv Sensors

Because i want to see something like a bigger "segnors loop" in action. Basically when cloaked, Boost, Decloak forward left, then 4 Kturn. Admire what the ship just did, then get blown to smithereens.

Easy checklist to determine viability

1.) Is it ACD?

If yes, yay! If no. into the garbage it goes!

More seriously, you're better off just running interceptors. You'll get silly maneuverable with phantoms, but they're already silly maneuverable and the presence of turrets makes it all rather pointless when you could be stacking green dice instead. You could go for the PTL route, but lower pilot skill and not nearly as many green maneuvers don't make it seem that effective. If you want to play casually and make woosh woosh noises while running laps around your opponent with Echo, though..

On the topic of other mods, I will say Stygium is actually pretty legit on generics and I had a lot of fun flying the 30 pointer Sigma (FCS, Stygium, Int Agent). Takes a lot of concentration and foresight to plan out the optimal cloaks and decloaks, but **** is it rewarding when you get it right

The Navigator will usually let you put yourself right where you want without giving up ACD.

It's not crazy, but there's not much reason to do it: usually, decloaking is more flexible than boost and doesn't consume your action, so usually people prefer it. With Engine Upgrade, you're essentially setting yourself up as an Interceptor with one additional Attack die and a worse dial.

So it's not the end of the world, but it's not up to the ship's full potential and therefore most people don't do it. If you want to try it, though, go nuts and then come back and tell us how it worked.

Easy checklist to determine viability

1.) Is it ACD?

If yes, yay! If no. into the garbage it goes!

More seriously, you're better off just running interceptors. You'll get silly maneuverable with phantoms, but they're already silly maneuverable and the presence of turrets makes it all rather pointless when you could be stacking green dice instead. You could go for the PTL route, but lower pilot skill and not nearly as many green maneuvers don't make it seem that effective. If you want to play casually and make woosh woosh noises while running laps around your opponent with Echo, though..

On the topic of other mods, I will say Stygium is actually pretty legit on generics and I had a lot of fun flying the 30 pointer Sigma (FCS, Stygium, Int Agent). Takes a lot of concentration and foresight to plan out the optimal cloaks and decloaks, but **** is it rewarding when you get it right

I prefer sigmas with spa and recon spec, lets you get a good stack of tokens for the first exchange, where everyone likes to go for the non cloaked phantom, cause whispers trained people way. 32 pt version with fcs added is extremely good too. Plus I very rarely use spa more than 2-3 times a game (not including a turn 1 cloak) so stacking defensive tokens is my priority