Well regarding food-safety, if you do not smoke overly doses of Limonene, it would not be toxic primarily. But you would have to swirl your Leave material inside of your Limonene-mix and this will never distribute the material evenly on the leaves, leading to a big variation of potency - which you also cannot see or detect when handling the leaves later on.
But the bigger problems are:
If you never go through a state where you have a crystaline compound, then you will NEVER be able to measure any dose and adjust any ratio of anything. Until the smoked effects are over you do not know anything about potency and it could be anything. While you may say "I wont care if its a little bit too much or too less" I would say: maybe this is true, but it is definetly (!) inconvenient to have all your processes become basically randomized.
Another problem that also Wolfnippletip said is: It will not evaporate completely and you do not know
A) how many actives are in there
B) the purity of anything in there - you could have a 3x amount of non-active material also inside
C) the amount of Limonene - it will be impossible to weigh the oily mess, but even if you get a real number, it wont mean anything
((
I can think that you may live in a place where you do not want to catch any undesired attention, which is a very common and logic thing, but it will make your results very inconsistent and also the process of experiencing your hard work.
And the last thing is that at a too big amount of Limonene, the mixture will start catching fire, as Limonene is flamable and of course this would ruin the flavor (not just in a cosmetic way, but it will be hard to hold anything from it in the lungs) and also the amount of vaped ingredients and at last it will become more unhealthy.
So this all sounds bad, but you could get around it by separating the Actives from the Limonene. I guess freeze precipitation would be the only easy way, but you would need to check out if it works along with Limonene.
