It doesn't matter emilson. They'll be updated just like all the stock, should that be required.
Before the advent of widespread electronic trading people frequently held stock certificates.
If you're going to keep them a long time put them in a safe deposit box.
In any case, my suggestion is, first, people should simply ask their broker how long it would take to get HMGP certificates specifically, and if they choose to request certificates, make copies and send them back, or keep them if you choose. At least they will be out of mm hands a few weeks keep them on their toes.