Even if the heating chamber reaches the boiling point of DMT, the DMT vapor is going to stick to various surfaces inside your kit and you are unlikely to collect any. To see what will happen try vaporizing a small sample of DMT inside a glass jar or bottle.

The oils will most likely have higher boiling points than DMT (~160°C ?). It means that DMT may vaporize first and you will lose it.

If you are feeling adventurous, go ahead, try it and let us know what happens.

Dont forget that Alkaloids are always present as the salt / ion in physiological state of the plant, thats why you can also have success when extracting with pH-neutral water (still lesser effectivity). And I think that the principle of steam distillation only works with unpolar things, similar to extraction with supercritical CO2. This means you can get everything out that is not present in a salt form in the plant material, like Limonene or any other essential oil compound - for example Carvone at Spearmint or beta-pinene in lemons.
Still I'm not quite into steam distillation, I did it once to get some Limonene - but the yield is very low if you do it yourself, a few ml for a dozen oranges

But if I am right it may be impossible to get any alkaloids with vapor distilation, as they will always be present as ions in solution. I guess thats actually good news for you, as you would try to use this as a possible defat step. All these "real oils" as told above are not alkaloids (not containing any Amine that can act as a base) and will therefore be exactly the compounds that you would normally remove by defatting.

But even if DMT would vaporize: then you would not loose it, as (based on your apparatus) you will have a cooling part directly above your heating vessel and this will condense all evaporated products into a second container. Therefore the evaporated DMT could only wander up into the condensation part and will be also caught by the condenser trap and transported into the collection vessel.
If it WOULD vaporize as a salt it would be dissolved in the collection vessel, so you would need to basify that and pull from it.
If it WOULD be present as a freebase in the bark, then it would either be forming a layer on top, like other oils collected from steam distillation or (more likely as observed in other cases) it would sink to the bottom as a voluminous solid.
But both of the last cases wont happen pretty sure and therefore you will still have your DMT inside of the heating vessel.

Nevertheless it would be interesting if there indeed are so many oils in the bark that it would be worth it, I never came across ACRB, but normally you need quite a good amount of heavily-oil-containing-material, like lemon or orange peel or spearmint leaves, to get some ml of oil. But the best way is to find out!!

Acacia flowers are distilled to produce an essential oil used in perfumery.

Have fun with your experiments. Rosemary works pretty well, but like BW says, you'd have to go big to get a significant amount.

There are some old threads about entrainment distillation of DMT freebase. I think someone (1ce) used cyclohexanol.