Ok, look at the BLP 3 circuit block you posted and look at yours. Two different part numbers.
If you really have a 3rd circuit, there should be a brass tube sticking into the venturi. If there isn’t one, it’s a 2 circuit carb.
Lots of guys use annular boosters. BLP sells them. I get mine from Mark Whitener who is Lightning Carbs. The annular booster (in my opinion) is the best option for most anything with a cold intake.
One of the reasons you are changing bleeds and not getting any changes is the emulsion stack you have. I can’t see from the pictures but unless 2 of the holes holes are not drilled through to the well you have all 5 of them open. You need to pin them to see what size they are and how many are open. If you don’t have a pin gauge set you can use drill bits to get the exact size of the holes.
I know it’s all the rage (still after it’s been proven it’s hard to beat a ”conventional” emulsion stack) to run all that emulsion but it causes what is called “slugging”.
Its what happens when you have a straw and you are trying to suck the last little bit of soda or whatever out of the bottom. You’ll get some soda and then some air and then some soda and then some air.
Thats whats happening with your emulsion right now. The booster pulls a “slug” of fuel and the it gets a “slug” of air and that continues on.
Its also what when you turn on a garden hose and you get some water and then some air. Until all the air is purged from the hose you keep getting slugs of water and then slugs of air.
In your system you never purge all the air because the emulsion is open to the Main Air Bleed.
I know it’s difficult and extremely expensive to buy stuff from the states. That really sucks. At this point, I don‘t think you have 3 circuit carbs and that’s a good thing.
Once you get your holes sized and mapped it’s pretty easy to change brass and block some holes. But we need to know what you are starting with first.
It sounds like T slot restricters are already in the main body so that’s good. We need to know what size they are as well.
Once we know that it’s simply a matter of giving you a good baseline tuneup to get you started and then your tuning changes will make a difference.