adding subdomain wildcard after setup

Hi there, I'm making my first go at setting up a paid sites network. I'm hosting on dreamhost. I don't want to switch to vps just yet so won't have subdomain wildcard setup until I'm sure if it's worth it financially.

Is it possible to start off manually creating the subdomains and then switch subdomain wildcarding on later?

Anyone did this before or know the nitty gritty of this issue?