I had been thinking of adding a laser to my SB but after seeing several purpose built lasers in action, I decided it wouldn't be worth the effort to modify my SB. For one, the fumes are going to be a real problem. Lasers generate a lot of smoke and unless you have some way of dealing with that, you're going to find it intolerable. If you have any sort of smoke/fire detection in your shop, it's going to go insane. Brady already went into the issue of low power.
The SB is total overkill for a laser. It might be fun as a test or hobby thing but I doubt there can be any production value in adding a laser module to your SB. Just my two cents.
ShopBot Details:
2013 PRS 96x60x12 (Centroid upgrade)
4hp Spindle
12" indexer
Aspire
Rhino
Fusion 360
Ferrari 360
Prusa MK3S+
Prusa XL multi-tool