I think the message we should take home here is, nothing is 100% safe, not even MXE. Don't fool yourself that it's absolutely, completely benevolent, even if there seems to be little to no harm from your doing it. Besides my own experience, there are many anecdotes online that for me prove the addictiveness of this substance. The addiction is quite weird for most people though, it only seems truly addictive as long as you have some in your possession. Try to think objectively about your use, ask your friends and loved ones, is your own usage doing you more harm than good, perhaps in areas of life you didn't previously think of? Take a break from it and see if your perceptions about how you feel change.