Here's a receptor occupancy chart.
It's true that everyone's ceiling dose is variable. But according to these charts, you don't reach full receptor occupation until after around 8-16mg
I find 4-8mg to be my personal ceiling/blocking dose. As in, if I'm taking more than 4mg a day consecutively, I am going to need a good 12-24hrs of no dosing in order to feel a full agonist.
But if I'm taking .5mg-2mg a day, I can absolutely feel a full agonist. It might be a bit muted & not as enjoyable, but I can still feel it. And theoretically, so should everyone else. I think a lot of people mistake the lack of euphoria as "blocking". But even if you don't get any euphoria or "high" from it, it can still provide pain relief that's better than buprenorphine alone. At least IME.
I don't think I'm a "rare case", I think most people just don't know how buprenorphine works & believe in misconceptions.
Buprenorphine is active in micrograms. I highly doubt .5mg (or any dose, as you put it) would block anything. You don't even have full receptor occupancy until you have at least 8-16mg of bupe in your blood. And this is variable for some people. Buprenorphine also raises tolerance & I think most people mistake the lack of euphoria when they take a full agonist as "oh my suboxone is blocking it"...Which could very well be the case if you're taking high doses every single day. Yet it's physically impossible for buprenorphine to "block" an opioid if your receptors aren't saturated. You may not get much effects, but anyone who knows what they're looking for can tell when they've taken a full agonist over a partial.
I also said if you're taking high doses every day, then you're going to need to wait 48-72hrs to let that come out of your body, yet you're repeating this as if I never mentioned it, which I think is misconstruing my point.
You can literally maintain on lower doses of buprenorphine in preparation for full agonist use. It's not impossible & actually follows along with the science & pharmacology of how buprenorphine works. OP is literally throwing the baby out with the bathwater because they think they're fucked because they take Suboxone. Yet as long as you lower your dose in prepartion for taking a full agonist, you can get it to work. And this isn't something a "rare case like me" can only do, anyone can do it.
Some one taking low, non-blocking doses of buprenorphine, will literally have receptors open for a full agonist to attach to. You won't get the all encompassing euphoria from it that you normally would & I think most people mistake this as "blocking", when really it's a tolerance issue. You will still get slight/moderate & even strong pain relief from the full agonist, especially depending on the dose. This isn 't something "rare" at all. It's basically why OP's doctor said he should cut his dose down in preparation, cause as long as he allows some of that buprenorphine to leave his body, it will open up receptors for a full agonist to attach.