I would 
EXTREMELY advice oral Harmalas + smoked spice.
Reasons:
- if you stuff your Harmalas onto the leaves, then your leaves only have 
100% - X% DMT, as you (of course) also need to vaporize the Harmalas. Therefore, if you are not a familiar smoker, it will be 
harder to reach a certain point of dosage, as you will also *waste* capacities by also vaporizing and smoking the harmalas.
= eating the Haramals before will completely 
eliminate the need to 
smoke more than totally necessary.
- 
Harmalas evaporate at much 
higher temperatures. Temperature control is not that crucial, if you can just need to focus on evaporating the spice (at 150 °C).
= in a vaporizer with a fixed temperature it will be 
hard to evaporate also the Harmalas and 
NOT burning SpiceAnd the most 
important point - also important if you are a PRO-smoker and can smoke anything in combination:
- Who tells you that your 
Harmala-Dosage of your Changa-Mixture it the 
BEST one? You put as much Harmalas into it, to get a decent effect. But you dont put TOO MUCH of them into it, because then you would only have harmalas in your mixture and too less Spice. So you have a ratio of like 1:1:0,3 or something like this.
But 
who tells you that 0,3 Harmalas is already the 
best amount?
If you 
EAT them you can eat 
ANY AMOUNT. And I can definetly tell you, that the 1:0,3 or even 0,5 ratio does MAOI-effects, but if you eat 
200 mg of harmalas orally, you will get a much 
STRONGER MAOI-effect. 
Eating like 200 mg or 250 mg will result in a 
much longer fading experience, so you can 
build your dose up much easier and much more conveniently.
I can definetly say: what is normally the ratio in changa is way below the maximum of MAOI-inhibition. 
= eating it can be beneficial to get even longer experiences AND if you are not a familiar smoker, you can easily just smoke your 1 dose in like 3 tiny doses, as you will 
1. 
have even longer time for the experience to fade
2. dont have to smoke the harmalas in combination, so when smoking you can 
100%ly focus on the Spice itself.
For all this reasons I completely abandoned doing Changa and I always eat the Harmalas before.
Just eat 1 dose of 150 - 250 mg and it will COMPLETELY be fine for your whole session.
Life is much easier with this 

 There is totally no downside.
PS: Last but not least: 
Smoking less substances and eating more is also 
healthier 