Workshop FastDL forces content download even if installed

Currently the resource.AddWorkshop file forces players to download all the content even if the player has the addons installed/subscribed.
I would like to have the server check to see the player has them installed so that the join time would be faster for people with slower connection speeds.
Is that possible and if so how?

The players will download all of it 1 time when they join they will download it then they leave and come back they don’t have to download again

I know that info but I’m wanting to know if there is a way to make it where players that have the stuff subscribed to and downloaded/installed can bypass the downloading of the addons.
Something like if client file exists then mount