Only in a limited capacity. You can pause the unit's expirations timers and add a new one; however, the unit will still show the (inactive) older expiration timer when selected, and there's no native way to obtain the original expiration time nor the remaining time in order to add a se t amount.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.