I don't have an MFLB, but I can use about the same amount (from what I've heard from MFLB users) in my NO2, and get pretty high. I'm pretty sure I have a low tolerance too lol, haven't really smoked in awhile, just vaped.
I was the same way, and then I didn't stop and my tolerance rose. Takes me about a trench and a half to get stoned for me.