since absorption rate between two methods will be different, peak concentration and time needed to reach that peak concentration will differ
How much? we can't know for sublingual harmalas since there are no scientific papers (or at least I have not read them), but at least we have some data about the peak and time needed to reach it if for oral dosages. So basically you will have to rely on isolated reports from users and your own experience to reach a conclusion
obviously taking more sublingually will increase the duration, but from my experience it is easier to overdose sublingually