I'm not familiar with your ink, so you should check with you tech first.
But when I have overspray, the only thing that fixes it is doing
a solvent flush. My method is to:
1 flush once
2.clean the outer print/head plate with a solvent soaked wipe to get the built up gunk cleaned off.
3. clean the print heads real well, with a new solvent soaked wipe .
4. flush a second time.
5. do three ink primes @ 2 seconds.
6.wipe and do a jet out.
Just to be clear, this is a solvent flush via the computer, I'm not talking about pulling the heads or anything like that.
And when you do a solvent flush you don't want the solvent sitting in your heads too long, so do your ink primes right after.
When I shut down at night, I do a ink prime and don't wipe, turn the head and and reservoir temps down to 25 and leave the printer on.
You don't want to cap the heads, just put something like a small piece of coro in front of the head box to cut down on air flow.