All psychedelics produce short term tolerance once the dose has fully kicked in, though some do more than others. I have ever met a psychedelic that doesn't, except for smoked DMT, which seems to keep working over and over again just as much, likely because it is an endogenous neurotransmitter in trace amounts, and is so readily and quickly taken into the brain, and then so quickly recedes. But yeah, 2C-B, just like any psychedelic, will produce short tern tolerance if you dose again after reaching the peak. In general with psychedelics, my experience has been that redosing more before it fully takes effect, even if you're coming up, will be almost as effective as taking the whole dose at once (except that it will absorb more gradually so the peak will be less intense, since it will not all reach peak plasma levels all at once, but in staggered bursts, each of which makes it stronger but it will be strongest if it hits you all at the same time).
If I redose after I've reached the peak. I find that all it seems to do is extend the peak for quite a while longer, and basically gives me a longer trip, unless I dose twice as much as an initial dose, and then I'll have a second peak that is as strong or even stronger. If I wait even longer and redose during the tail end, when I'm on the plateau but it is fading away slowly, it has even less effect, and basically just makes the ending stage, where the plateau slowly fades away to nothing, last a lot longer. And then for a few days, you will reuire a higher dose to reach the same place. However, that said, I usually trip 2 or 3 days in a row at music festivals, quite successfully. I do this by rotating classes of psychedelics. Basically, what I have concluded through ungodly amounts of experimentation, is that a specific psychedelic drug produces the highest amount of tolerance to itself. It oroduces a slightly lower level of tolerance to other drugs in its family, and then category... for example, mushrooms (ie, 4-HO-DMT) produce nearly as much tolerance to any other 4-sub tryptamine (4-HO-MET, 4-AcO-DiPT... in general, 4-XX-XXT, any of them) as it does to itself, but only slightly less. But it produces less tolerance to the 5-subs than it does to the 4-subs (so taking 5-MeO-MiPT, for example, the day after 4-HO-DMT would be more effective than taking 4-AcO-DET, but again, not a lot more effective). Then beyond that, any typtamine at all will have more tolerance from it than any phenethylamine or lysergamide.
Interestingly, my experience has been that tryptamines produce the least short term tolerance to other psychedelics of the 3 classes (phens, trypts, and lysergamides), then phenethylamines, then lysergamides. For some reason, if I trip on LSD, I have a hard time tripping hard on any other psychedelic the next day. So when I am planning to trip multiple days in a row, I save the LSD for last.
All of this is generalized... there are some exceptions. For example, the DOX family (DOC, DOB, DOPr, etc) seem to cut right through any tolerance I have and I will trip regardless of how hard I went the previous days. However, they also produce a lot of tolerance to all other psychedelics. So in a festival setting, I usually actually take DOC the last day, when I wake up feeling rough and exhausted. And before long, I feel amazing, and have loads of energy and have the best of days and nights. In fact, I eem to be able to trip about equally hard both days on DOC if I take it 2 days in a row. I just take a slightly larger dose the second day.
I have found that when I want to trip multiple days in a row at a festival, I can successfully do it every time by alternating psychedelic families. And I get even better results throwing an empathogen in on the second day, because those produce only a small amount of tolerance for psychedelics, if any. So I might choose, on a 3 night festival, to do mushrooms the first night, LSD the second, and DOC the third. Or more commonly, something like 2C-B combined with a bit of MXE or 3-MeO-PCE the first time, then AMT the next day (AMT is great because it's kinda trippy but mostly an 18 hour long roll... so it serves as an empathogen and a trip, but seems to mostly proeuce tolerance in the serotonin releaser sort of way and leaves you able to take classical psychedelics more easily the next day),and then LSD or DOC the last day.
And then, I go home, get good sleep and take care of myself for a while, and don't trip again for a month or so, in order to prevent long-term tolerance from developing.
All of this goes out the window if you regularly trip multiple days in a row. Then long term tolerance starts to set in and you become a hardhead and even after long breaks, you need to take way more than most people to be able to get more than weak effects. You want to avoid this at all costs, I once tripped 3+ times a week on average for 2 and a half years or so... I got to where I literally just couldn't trip, except from smoking DMT or taking absurd doses. It took 3 entire years of not once touching a psychedelic before I could even get anything from them again, and then a couple more years for me to not still be a "hardhead". The good news is, these days, I rarely trip, and I am more sensitive to psychedelics than I have ever been before.
