Will a PSW long stroke equal my DGI FN CHF upper save the dirty BCG

Try not cleaning it. Like ever.
Also don't touch the bolt while shooting, it's going to be hot and that's okay.

Or, just clean it when you get home. That’s plenty of time for it to cool. The bolts and carriers in my rifles wipe clean with a paper towel. Takes longer to break down the gun.

The bcg should essentially be clean with a quick spray of clp and wipe down. Legit 30 seconds. You can go a long time without cleaning your bcg. Just keep it oiled and it will keep performing. I have bcgs I haven't detailed in thousands of rounds. Just quick clp, 10 second wipe wipe down, a bit more clp and it's back in the gun.

The problem is that the Flashpoint for most lubes used on AR rifles is very low. CLP is around 150 degrees if I remember correctly. The gases entering your BCG are 400 - 500.

Thus after a few rounds your lube burns off, the carbon deposits get hard, reliability will eventually wane, and cleaning becomes a pain.

I will be marketing a lube I made here soon that is an outstanding performer for exactly this problem. I need to get home from my current trip and get a commercial account here before I can though.

I will tell you I put some on the piston head of an AK and then ran 700 rounds through it in one range session. I gave the piston one wipe with a napkin and all the carbon came right off. I should still have the pictures somewhere.

In short, the problem is not your rifle, but your lube. Until I am able to market my stuff, just use a good 40 wt motor oil.

I cleaned one of my rifles the other day. First time since I think 2017 or something like that. I didn't remember what brand of bolt carrier group I had to be honest.

It is a myth that piston system is 'cleaner', even more a myth if shooting suppressed.

Unless there is a specific need to keep your gun spotless then just do it every now and then. 40 rounds is honestly a total joke. Try doing it like every 500 or 1000 rounds or something like that.

Cleaning depends on the use of the gun. If you are a bench rest competitor then you will clean a lot more often. But for average use it is a waste of time.

I definitely do not know your motivation for trying to keep your rifle spotless but odds are it's because you like having stuff rather than anything to do with reliability or function.

As far as lube goes I've migrated completely over to grease. In my opinion it's way better than liquids.

I've had lots of 500-1,000 round range days with AR's without a hiccup. Dirty doesn't mean bad. A little bit of oil on the guide rails of the BCG and the gas rings and the back of the bolt lugs and it's happy. Add a little lube after a few hundred rounds if you want. They run just fine when 'dirty'. It's just carbon fouling.