Multiple Occurences

If a user has a screen open and tehn goes into a few more screens then opens teh first screen again,  will that cause any performance issues?   We have people that for instance will open Interim Entries then go into many other. Then after 4 or 5 different thing, they go into their favorites and ope Interin=m Entries again.  I would think that they should go back to the original one but if they don't, I was just wondering if that would cause any problems.   I am trying to get them to not leave screens open if they aren't using