You might also take a look at some of Nathan Russell/Peril Planet's FU2E-adjacent designs - Neon City Overdrive, Star Scoundrels, or the ones he wrote for Osprey, Hard City, and Tomorrow City.
Having spoken to Nathan on a few occasions, including recording an interview with him for a local con, I don't think he would mind you putting out a free PDF of optional rules for Action Tales.
I imagine if you contacted him using the form here, he'd even give you express permission.