TBH 2 crew slots would probably be enough... I wouldn't be against Jabba giving an extra Illicit slot as part of his abilities to represent extra modification to the ship he was in.

So effectively you are paying a crew slot, and then swapping the second crew slot for an illicit, that would be in character and mean you don't end up having one card taking up most of your slots.

Edit: On second thought, just make Jabba require 1 Crew slot and 1 Illicit slot. It does the same thing without strange interactions of too many crew on other ships.

Firespray-31..... - 1 crew, 1 illicit

Hound's Tooth.. - 3 crew, 1 illicit

IG-2000........... - 0 crew, 1 illicit

Punishing One - 1 crew, 1 illicit

Shadow Caster - 1 crew, 2 illicit

One of the versions I made doubled all discarded illicits in the squad with ordnance tokens, with a note in the card to use him as a Reference Card if he get's discarded so the tokens don't become useless. That would tend to favor swarms which could represent Jabba's minions, and/or his Star Jewel Guard.

2 Crew slots. Add an extra modification. Double all discarded illicits...

something that compliments/synergises with these maybe...

This earlier idea was on a similar track. I was tempted to go with 2 crew + 1 illicit, but I don't see this as a good idea any more because like many of the restrictions that Huge ships have, I suspect not using illicit slots will be one of them, so no versions that add illicit slots to Jabba's ride would be likely. It's too bad because I would have favored a Jabba that adds 2 illicit slots also.

Well you already have the Shadowcaster with 2 Illicit slots. So I'm not sure a YV-666 with 2 would be an issue, seeing you are losing most of the YV-666 advantage (the fact it can mix and match crew) by using most of it's crew.

On a Huge ship I can see the problem. Inertial Dampers seems the biggest one, Burnout Slam too.

This earlier idea was on a similar track. I was tempted to go with 2 crew + 1 illicit, but I don't see this as a good idea any more because like many of the restrictions that Huge ships have, I suspect not using illicit slots will be one of them, so no versions that add illicit slots to Jabba's ride would be likely. It's too bad because I would have favored a Jabba that adds 2 illicit slots also.

Well you already have the Shadowcaster with 2 Illicit slots. So I'm not sure a YV-666 with 2 would be an issue, seeing you are losing most of the YV-666 advantage (the fact it can mix and match crew) by using most of it's crew.

On a Huge ship I can see the problem. Inertial Dampers seems the biggest one, Burnout Slam too.

I think you missed my point, 2 or more illicit slots added to a large ship is't the problem. As I said I'm for that. If Jabba can make a large ship have 2 or more illicit slots, then when equipped to a huge ship he would add odd illicits, as you've pointed out.

The only way I think FFG will have Jabba adding illicit slots is if they stipulate those slots as Large ship only, which might need some awkward wording - "If equipped to a large ship add an illicit slot."