It doesn't really seem too far fetched to make this work by redosing both dmt and haramalas, but it's hard to say what doses to take and how to time it. DMT does seem rather unique when it comes to tolerance, perhaps since the body produces small amounts of it? If dmt has some purpose as a neurotransmitter, perhaps the body is more vigilant in regards to tolerance build-up. Could you imagine if serotonin caused a rapid build of tolerance in the same way as other tryptamines? Endogenous production could not keep up with the ever increasing demand for it in our system. Granted, this is not the same thing since we are talking about introducing incredibly large amounts of dmt into the system compared to what would normally be present. The best way to find out would be to try redosing multiple times at the same dose to see if there are diminished effects. One word of caution there is that haramalas may be neurotoxic at really high doses, and it's hard to say if there would be accumulation in the system from redosing too soon. Most likely if it did accumulate it would make one feel physically ill to the point of not wanting to continue the experiment long before risk of neurotoxicity, but this is just speculation.
One thing to note too is that tolerance to haramalas generally does not build up fast enough to have to up the dose for them on this type of journey, and I suspect that redosing at the right time would require only about 50-75% of the original dose to effectively inhibit mao-a. For example, if one was to take 200mg haramalas (eg, purified syrian rue alkaloids), wait 45 minutes, then take 60mg dmt and wait until just after the peak to redose 100-150mg haramalas, then another 45 minutes or so later take another 60mg dmt, etc...No clue if this would work, but if repeated redosing of haramalas causes a progressive increase in body load then perhaps it would be the way to go. Anyways, lots of speculation overall. Kind of interested in testing this now, but have little time or resources to do so at the moment.