"Can you do a cashless sell with warrants like you do with options, I don't know."

Quickly before I go to gym.
IMO, If you own the warrants in a margin account, as I do, and have a high enough margin availability to cover the cost of the shares, it would be a cashless event, so to speak. The brokerage house would just exercise the warrants, take the money out for the margin cost of the shares and give you the profit. Of course they will charge you a commision fee just like buying and selling shares.

Now in an IRA it might be trickier, but I imagine if you had a high gain on the conversion of the warrants, the brokerage house would work with you, for a commision fee, of course.

This is just my thought...