I follow this pretty closely as I have become a bit of an amateur "stamp collector".
It will seem overwhelming at first, but once you go through it- it's not bad. Silencer Shop is your friend. Download the app. Find a local dealer that has the kiosk. That way it will handle fingerprints, etc. If you want to add someone from out of state to the trust, they just have to find a dealer with a kiosk or get prints and mail them in. A gun trust for multiple people, wife, brother, that one guy you know who you trust with your life and combination to your safe, etc. is about $100-125. And you are done. Remember, without this type of trust, if you are out fishing and your wife wants to go to the range- she can't take the suppressor.
Once you get the gun trust set up, you go to SilencerShop.com, find what you want, order it and fill out your Form 4 through their website. Pay an extra $5 and they will review it for you for completeness and kick back anything ATF will have an issue with. A month or so later, it gets transferred to your local dealer where it sits "in jail", but you have visitation rights.
Once you are in their system, they will handle everything. If you go to add a new item and your photo is expired (has to be less than a year old), they will alert you, open the app, take a "selfie" and you are done.
Unfortunately, wait times are still in the 8-12 month range. And the best way to handle the wait is by forgetting about it.
I have the Yankee Hill Machine Wraith that I use on my PCC with both 16" and 8.5" upper. Trust me, an AR pattered rifle, in 9mm, with an 8.5" bbl and a suppressor will go through a TON of ammo. A good 9mm can will handle 300 BO subsonic.
I also have a Yankee Hill Phantom for my AR in 223/5.56. I'm a fan of Yankee Hill as the QD mount they have is really good. The one for my 9mm is also a flash hider. The one for my 223 is a muzzle brake. So, if I shoot without the can, at least I have a brake on it.
I also have a Tac Sol rimfire can. And yes, a rimfire can is a different beast. It HAS to be able to be disassembled.
I shoot just jacketed through my 223 as I don't shoot enough to bother casting for that. If I want to shoot a lot of AR cheaply....I'll use the PCC. With that I shoot 147g powder coated and have done very well. 1.5-2" groups at 50 yards with an unmagnified red dot and AARP eyes. I tried Hi-tek and while the barrel didn't lead....the flash hider did. So, PC it is.
As to HPA or SHARE act. Forget it. Not going to happen. Completely dead. There was two times they were headed for votes and were making real traction. Congressional Baseball Shooting and Vegas Shooting. I'm not saying it was linked, but it's enough to make it a political deal killer for at least another year or two. All these people who say "I'm waiting for HPA or SHARE act so I don't have to wait for my stamp", could have had them for a year by now.
There is no "one can to rule them all". Anything that can handle rifle pressures is too heavy for pistol. My rimfire can is less than 6" long and about 1" in diameter. I can't imagine hanging my 223 can on the end of my Buckmark. There are SOME crossover. If you get a good .30 cal can, you can use that on 223 rifle, it just won't be as quiet.
It's about more than the size of the hole. Pressure has a lot to do with it, as does weight.