Well, it does sound plausible / likely that it would be the pseudo-irreversible binding, right? But of course, the dosage is also orders of magnitude lower so you would need to know how those kinds of binding compare to each other - you just don't know if one of them produces more activation vs tolerance or less, just like we are mostly clueless about the functional selectivity anyway.
For me it is definitely not consistent that I need more than a week between acid trips, but I don't remember my frequent shroom tripping well enough to compare my own experiences with tolerance and compare... I developed some chronic tolerance now though, mostly from ETH-LAD and it seems to apply to psychedelics in general like you'd expect.
Tolerance and cross-tolerance gradually go down but I don't think in a linear fashion but rather like (inverse) exponential or something - recovering fast at first but then slower later. Also trips produce psychological tolerance, if you stack up meaningful trip experiences it becomes much harder to get the same sense of novelty and wonder - possibly because of particular mechanisms in the brain that register novelty that get desensitized. After 10 days if you don't have a tripping habit most of your tolerance should have dropped but this is hardly ever 100% reliable like psy experiences are never anyway, especially not shrooms which vary in potency even in the same batch.
Therefore, as a rule of thumb always try to wait longer if you can... but this whole rule of thumb of waiting a week seems to be based on getting past the knee of the curve, recovering fast from the large part of the very noticeable tolerance and ignoring the more subtle part. Keep ignoring that subtle and long winded part over and over again though and you get yourself that chronic tolerance that is bugging me now.
Alternating tends to be good yes!! This is most true for the most differently acting drugs (such as anxiolytics or stims with different mechanisms of action), sure, because you give the non-overlapping (crossing) part of the tolerance time to recover. Although alternating with certain serious drugs could have different downsides possibly, like forcing so much overall change and up/downs that it is unusually destabilizing. Probably not a particular concern with psychedelics if you ask me, if psychedelics are destabilizing it usually won't be because of those reasons IMO.