What do the pros use to replace the factory chip guard from the underside, ie when doing a panel replacement or work in the wheel wells?

Original owner of my '94 Civic had the bottom Ziebarted, and I'm trying to get it back down to the factory stuff so I can give it a coat of machine grey paint. I'm having some luck with slow reducer, rags, and a wire wheel... painfully slow going though.

Problem is that when I get at it with the wire wheel it's making short work of the factory chip guard & seam sealer in the fender wells too, but not quick enough that I want to do it all. It's down to the e-coat and I've breached it in a few spots, so I'll have to get some POR-15 on those areas as well.

So I'm weighing my options for removal/replacement

I'm familiar with the Crud Thug and it's Wurth counterpart, don't want to go all the way to bare metal. Bottom of the car is/was pretty cherry when I started, aside from the nasty Ziebart.

I've read that a needle scaler is good for removing undercoat but I'm not sure if I want to strip it all since the car will still see use (track toy/occasional street). It's also not enough of a weight savings to go after it for that. So what is good to replace it? Are the stone chip primers I see online similar to this stuff?

The other side of the coin it that a bare underbody does look nice and is really easy to keep clean, but is prone to chipping from all the crap on-track and road and is noisy as hell.

Opinions on how I should proceed are welcome!