Thanks for the suggestion @Duffman 
It’s something we have in mind. We are still unsure of the implementation but will propose something once the v1 of the feature is out.
I don’t think we’ll split this feature between CE and PRO though. The logic we are usually following is that whatever is related to productivity as an individual user or in small teams go to CE, and features related to scalability and compliance go to PRO. In our case, icons and even custom icons belong to the first category I’d say: productivity as an individual user or in small teams.