Well, today during my lunch break I spent some more time with the sprayer.
The Flo Master sprayer has a different nozzle design than the sprayers I have at home (which match the videos I’ve seen online of people hacking cheap sprayers into foamers).
I spent some time digging through my box of spare small plastic caps trying to find something that would slip over the nozzle to add some scotch-brite style material to aerate the dispensed fluid as I saw in the videos. Not finding any caps I was willing to give up (I use them to cap off lines/etc during repairs), I remembered how at times the sprayer would foam just when the fluid level would get low and you were tipping the bottle around. The other part of the online how-to has you poke a small hole in the pickup tube.
So: Let’s try this. I used a pick and poked a hole in the pick up straw well above the fluid line. I took some old (emphasis on old) Zaino car wash that’s been hiding in my box, added an unscientific squeeze into the water in the sprayer, sealed it, and bumped it to 40psi.

Here’s the sprayer with fitting:


And here’s the output after playing with the factory nozzle a little:


Way better than I was expecting! At this point I’d feel comfortable actually flushing the sprayer out and trying it with some of my good chemicals.

Next thing on the experimentation to do list is to-
A: See how long it dispenses and how much coverage you get between recharges.
B: Try connecting my little cheapie tire inflator and see how annoying/effective that works. It’s a little cheapie Micro Start inflator that connects to their jump packs (or a cigarette lighter). If the bottle runs out of pressure crazy fast, I could use the little inflator and have the jump pack in my back pocket to power it (it’s one of the little jump packs, not huge ones!).