Pre-treatment of MDF?

Greetings! New to group and not really a precision woodworker, but love to 'do it myself' whenever I can.

I'm planning a new project, a bit off-beat, in which I'd like to use CNC-routed MDF parts in place of machined metal ones. I chose MDF because of its density and durability; actual strength isn't a primary concern because very low forces are involved. However, dimensional stability could be an issue, although the final home for this project will be indoors and climate-controlled.

The Web gave me some info on MDF stability, recommending covering the surfaces with high-pressure laminate, which I was planning to do anyway. However, there will be back-door access to the raw material here and there, so I was wondering if any sort of brush-on sealer might help protect these areas. My dad swore by Rez Sealer back in the day, but like a lot of good old standbys it's now a known carcinogen and no longer sold. Some of the available sealers are water-based, which seems wrong to me, so I wondered if someone here might have suggestions.

Also, I welcome any comments on CNC-routing of MDF in general, whether it's a customary practice in furniture-making, etc., and what sort of tolerances can be expected to be held. I don't own or have access to CNC gear and would appreciate any tips on where I might go to get one-off parts made. Many thanks in advance!