I know you like SheldonSoft to be around so you can make occasional business-related jokes, but yeah, it's been a long time since Sheldon last checked in on the business.

I don't know if you want to do another extended story in Sheldon, but I was thinking it might be a good story for Sheldon to lose the company/quit the business. I would assume that Gramps has set aside a certain amount of Sheldon's income for college or whatever, and that Gramps has his own retirement income for them to live on.

Or you could go full circle, have Sheldon lose the company, adjust to the loss, and then regain it or start a new company.