I don’t know if this particular problem was already raised before, anyway,
I found a bit scary that a simple mistake in manually specifying the gas could propagate a transaction, paying a very high or a disastrous fee (in the MM extension UI).
An error like typing one or more extra numbers (you will use gas at least 10 times greater than needed)
- an erroneous click on the “Enter” key (it is so close to numbers in the numeric keypad)
- or by an “unconscious” click on the “Send” button