I intended to use my Mi through water, but the flavour is so good with the short stem that I've never tried water again after my first attempt (my one and only combustion event so far).
I think that the reason I combusted (other than over enthuiasm for a huge cloud) was that the bong removed all of the heat feedback that guides button feathering.
Even though I went to the trouble of shortening the joint on an 18/18 M-M adapter I've never gotten round to trying again as the taste (and effect) is so good that I don't want to compromise it with a water tool!
I have a very low tolerance (rising rapidly though!) and generally prefer micro-loads with all my vapes, but the temptation to do 60-70% full bowls for the big gobs of flavour often leaves me in a near vape-coma!
I've experienced a hot spot while riding the button hard and simultaneously drawing very hard, but also when riding & drawing very slow.
I just go for a medium draw, and control heat with the button now.
I do get hot-ish spots on occasion, then I just stir.
Once I get a long stem which actually fits (or grind down the supplied one) I doubt I'll bother with my plans to use a water tool.
Despite loving bongs/bubblers I really don't think I'm going to need one with the Mi'.
I hope you eventually find satisfaction
@Milkytime, I imagine you will, as this is a great vape.
Good luck.