I am renovating/rejuvenation 3424 and I'm thinking of integrating the puller system with the spinnaker halyard (the same principal as the pole launch system on Laser 4000). has anyone tried this before?

I've thought about it. I decided friction would be a problem and it never got further than the paper i drew it on.

I think friction can be avoided with correctly positioned blocks. My concern would be getting sufficient tension in the puller. Using the halyard would require somewhere in the region of an 8:1 system. the knock on effect of this would be that to get sufficient travel the tail of the puller would have to go up to the bow and back again. this means that when the kite is stowed, the halyard would also have to go up to the bow. this would mean that when the kite is up there would be 3m of extra halyard floating around in the bottom of the boat, or worse still hanging out the front.

I can think of a way of doing it but though it means one fewer string to pull once hoisted the down side is not being able to put the puller on independently for stepping the mast & dropping the jib, not convinced it is worthwhile.
If you run the halyard to a turning block near the front of the centrecase before the cleat, back down the side of the case to a running block, then forward again to the cleat, then the block on the bight will be pulled forward when there is tension in the halyard, i.e. after you have hoisted fully, & you could run the string back forward to tension the puller.  No string in the bottom of the boat but a bit of extra length on the halyard and you would have to work out the leads properly.  8:1 is about standard on a puller anyway.  And needs a bobble on the spinny halyard to stop at the sheave.

Another thing to remember is that you will be pulling the halyard for longer before finishing the hoist. I would prefer to get the puller on before the mark then get the kite set asap. Shouldnt be difficult to set up but this may be the reason its not been tried before.

Another approach - on 3547 - I've removed the puller and reconfigured the snodger so that it also acts as the puller. A strategically placed stopper (with the snodger pulled on) allows me to step the mast and remove the jib as normal. Now sailed with the set up about 10 times and found no adverse reactions.
We will find out more when Tim sails it at the Champs.