My experience with psychedelic tolerance is that indeed all psychedelics are somewhat cross-tolerant. The most tolerance is produced against the same drug, ie, if you take, say, 4-HO-DMT, then it strongest tolerance will be towards 4-HO-DMT. The next strongest tolerance is towards the most similar compounds. So again assuming you took 4-HO-DMT, you will have stronger tolerance against 4-HO-MET or any of the other 4-subs than against any other psychedelics, other than 4-HO-DMT itself. Then others in the broader family, ie, any other tryptamine. You'll have less tolerance against 5-MeO-MiPT or DPT than you will against any 4-sub tryptamine, but still more than you will against any phenethylamine or lysergamide.
In general (with exceptions), I find that tryptamines produce the least overall tolerance among the 3 broad classes of psychedelics, and lysergamides produce the most. Smoking base tryptamines seems to produce the very least and for the shortest time... smoking DMT can be done near-daily for periods of time without much loss in effects (other than behavioral tolerance to some extent - I will mention that below).
There are 2 kinds of tolerance... physical, and behavioral. Physical tolerance is what we normally think of by tolerance, the temporary downregulation of receptors that makes it harder to get the same effects in consecutive trips. This willmostly disappear after a week, and fully after 2 weeks. I'd say at a week, it's 80-90% or more, depending on the drug. Some drugs seem to produce more tolerance and for longer than other ones. It may have to do with how strong of an agonist they are. For example, the NBOMes seem to produce very strong tolerance, and they're full agonists. Likewise, DOC is a very strong (maybe even full, I can't remember for sure) agonist, and seems to produce strong tolerance (it will also cut through the tolerance of many other psychedelics)
The other kind of tolerance, I call behavioral. This is basically how novel an experience is to you, and it's related to, but different from, physical tolerance. You can decide to adopt an approach of calculating exactly how much time needs to pass until your physical tolerance is totally gone, and then always trip then, essentially trying to responsibly allow your brain time to recover, but fitting in the maximum number of trips that you can. When you use this approach over a long period of time, you start to notice less and less powerful and unique trips, even though you're allowing enough time for your receptors to upregulate. This is because of behavioral tolerance. Essentially, when you trip too regularly for a substantial period of time, your mind just gets used to it, and it starts to feel more and more normal. So the same amount of the drug reaching your brain produces an effect that feels less strong, and produces less novel and exciting perceptions. This sort of tolerance can begin to approach a permatolerance sort of effect. At this point, you need to take a long break and think about just not tripping until you're either in a different place in your life, or taking psychedelics in totally different situations (like if you normally trip by yourself and listen to music, try tripping with people out in the world, or vice versa. This will cause the experience to feel less "normal" and will produce a more profound and novel experience).
I used to trip WAY too often for several years, when I was younger. Like 3+ times per week, consistently, for 2 and a half years or so. It got to where I basically couldn't trip anymore, it became like how weed is for people who are 24/7 smokers, I got a nice feeling but it just felt more or less normal. Eventually I wore myself out from lack of sleep and crashed my car and realized I had to make a change. I didn't trip for 3 whole years, except one time at the 2 year mark. That time at the 2 year mark, I still barely tripped. After 3 years, and a concurrent shift in my life where I was living a new sort of life and having new experiences, I started to be able to trip again fully. Since then, I use psychedelics much more sparingly and I always have strong and good trips. I don't set myself wait times, I just trip when it feels right. This can range from months in between trips, to every weekend, it just depends on what is going on. I tend to trip more in the summer. The most I trip is at music festivals, and often I will trip 2 or 3 days in a row, or rather, do drugs 2 or 3 days in a row. What I do to make the most out of that is take drugs from different families each day. For example, I'll take LSD or mushrooms one day, then MDMA or something rolly the next day, then DOC the last day, something like that. When I do that sort of thing, I make sure to take longer before my next trip. I make sure never to trip just because I'm bored, because that just starts to make it feel more like an everyday thing that isn't very special or novel.
In short, to directly answer your question, if the situation calls for it, you can trip before 2 weeks, and get 2 good trips that are both worthwhile. But don't make a habit of this, and try not to develop a pattern of always counting down the days before you can trip again, because this sort of thing will lead to feelings of permatolerance eventually. It's best, in my experience, to leave tripping for when it feels right, and never use it just because you're excited to try it again as soon as possible. Sometimes the "right time" can be tripping twice in quick succession. Sometimes the "right time" is separated by months, or even years.
