Is there a good way to reduce the hard edges that spraying into masks traced off vinyl decals would leave behind, when not using a clearcoat? I only have a quart of the dark gold and a siphon feed gun, so I can't do a whole lot of tests and mistakes. The plan is either try to use the decals, cut out with an xacto knife, as a masking tape, or cut out a stencil mask using the decals as a guide. Either way I'm adding a couple layers of the same John Deere "Blitz Black" paint I have, but using a hardener so it comes out semi-gloss.

 

I just came across these, but I don't know if this will help you.
https://www.sealitpen.com/

 

They actually didn't leak around the edges like most people on the internet said they would, at all. I spent a whole day testing on a spare hood.
The regular diecut decals from Hawks/Pheonix can be used as a masking tape, if you are super super careful when picking them up.
The regular pinstripe tape from the parts store adheres too well ands rips the paint off.
Orange and yellow auto tape are pretty good too. Green auto tape leaves a fuzzy line.
Cutting decals out of those auto tapes was a completely absurd idea, it's a tremendous waste of time and impossible to get perfect without a laser cutter or something.
Implement paint will stick over regular activated acrylic, within the repaint window, and if the implement paint is activated as well.