I just realized that the "Advanced Cloaking Device" --which reads After you perform an attack, you may perform a free cloaking action -- says TIE Phantom only modification. BUT the "Stygian Particle Accelerator" --which seems to read When you either decloak or perform a cloaking action, you may perform a free evade action" -- does NOT have the TIE Phantom only qualifier.

This opens up the way for either a modification that grants cloaking or another ship that can cloak in the future. Are there other ships that can cloak? If it's a modification, how much would it cost? [Math folk I bet you can deduce this] Thoughts?

I just realized that the "Advanced Cloaking Device" --which reads After you perform an attack, you may perform a free cloaking action -- says TIE Phantom only modification. BUT the "Stygian Particle Accelerator" --which seems to read When you either decloak or perform a cloaking action, you may perform a free evade action" -- does NOT have the TIE Phantom only qualifier.

This opens up the way for either a modification that grants cloaking or another ship that can cloak in the future. Are there other ships that can cloak? If it's a modification, how much would it cost? [Math folk I bet you can deduce this] Thoughts?

I highly doubt that there will be a mod for adding the cloak action. Stygium cloak was extremely rare and only placed on a few (read: elite Imperial) ships. I could see the action show up on other (Imperial) ships, such as the Star Courier (Darth Maul's Scimitar had a stygium cloak, and it was used by the GCW-era Inquisitor Valin Draco) and the Rogue Shadow, though.

Good observation on rarity making it unlikely to be a modification. This begs the question of what future ships (if any) FFG has in mind. Do we really see Rogue Shadow coming up as a future ship? (For which faction too?) Just a curious door to keep.

Yes, it leaves room for more ships with cloaking ability.

However, the ACD confers the ability to cloak. To make sure that it only goes on the Phantom, they made it specifically Phantom only.

The SPA is cloaking dependent, it only functions when the ship cloaks or decloaks, there's no need to specify it being Phantom only as the Phantom is the only ship it could go on and still be useful.

You don't put an Engine Upgrade on an A-Wing or Interceptor or a Targeting Computer on an X-Wing or a TIE-Bomber.

And you shouldn't put extra rules text if you don't have to.

Not to mention it will prolly have a specific icon that only the phantom has in the upgrade bar.