Go for at least 180mgs to 200mgs, preferably 200mgs of Harmalas in a capsule, and then anywhere from 30 minutes to an hour later take your DMT. I've never needed two separate doses of Harmalas, i take my Rue seed powder capsules, or my freebased Rue extract capsule, or my freebased purified Harmala (Harmine/Harmaline) extract capsule, and then 30 to 45 minutes to an hour later i take my Mimosa or Acacia residue capsules or tea, works like a charm.
Ime it is definitely better to separate the DMT and the Harmalas, take the Rue/Harmalas (or Moclobemide) first, wait for MAO-A to become fully inhibited in the gut, and then take the DMT/DMT-containing plant. Always works, no duds, as full on as it can be, you just have to try a few different time windows to see when gut MAO-A inhibition is at it's peak. If you take the DMT too soon or too late, MAO-A might not be inhibited fully enough and some or all DMT will be inactivated, so it's best to wait until gut MAO-A is fully inhibited and then take the DMT. Encapsulated Harmalas, i think, tend to inhibit gut MAO-A a bit longer than Harmalas in tea form, though i still need to experiment around more with Harmala-containing teas.
Remember, the more Harmalas/Rue/Caapi/Moclobemide you use, the less DMT you will need for full effects, a full on dose of Harmalas would make 150mgs of DMT really potent so adjust your Harmala dosage first, then when it's good, experiment around with the timing of when to take the DMT, and then experiment around with the DMT dosages. Also if you consume Harmalas regularly, the Harmala dosage can get stronger due to the reverse tolerance so as you go along you can reduce the Harmala dosage bit by bit for a relatively consistent Harmala dosage, but if you take it like once a week or less it shouldn't be an issue.