Maybe one of these guys to total the time used up, each player is given an allocated time to play the entire game, how they use this time management is up to them. Time runs out there finished. How long ??? 35min or 40min per side. Idea???
The biggest problem with the chess clock idea is that in the turns there are many parts of the phase which both players participate such as planing and modifying opponents dice. In games like chess or other table top games like warhammer a player completes all their action in a single unbroken turn in which the chess clock will work. X-wing turn doesn't play out like those so the chess clock won't be effective.
I defy you to play 6 minute turns each with 16 ships on the table, when both players have been playing the game for less than six months.
On the other hand, playing 6 minute turns when there are only 4 ships on the table is laughably easy.
Having a game rule that punishes what type of squad you build is absolutely godawful design, and has no place being implemented.
There is nothing at all wrong with the current system, which is "If you suspect slow play, call over the TO".
It is more for competitive play with players who understand their lists. I also offered a 6 turn option which gives 10 minuets a turn for those that can play a little slower. Sure those with more models take longer to move their models but the model count spread of 2-8 is way less than some other games which could be 4-30 or 8-100.
Don't get me wrong playing only 5 or 9 turns by the end of the round doesn't mean that the TO must penalize someone. It is just gets the TOs attention, likewise that if the TO is called to a table that has gone on for 15 turns due to a slow play complaint and then the TO can tell the player to play it out.