It would be fine to try it at 100V to see how the unit works, it should not damage the power supply or the DMM. 100V should be just enough for the DMM to work normally.
Thanks
The problem is I have to use an original EHX supply, because if I try to use any other 24v adaptor the jack will not fit. It just happened to me with a DMMxo, and I wondered if all the other 24v pedals also have a smaller jack, so you can’t use other adaptor.