I saw another brand, Repel (also at HD), which IS water-proof and seems thicker and better quality (and prettier!).

Conversion Varnish is the industry standard for finishes because you can apply it thicker than other finishes, it is durable, and still has a bit of elastisity to it.

Many think just make the wall thicker by adding layers of drywall and insulation.

I was going to do ceramic tile in the bathroom, but stumbled across the new groutable LVT tiles at Lowes (peel and stick but much thicker than the previous versions). 

Keep cost down and do a simple vanity, new toilet, an over head recessed light, and simple white subway tile all the way up, or throw a shower insert in there and be done.I have a rental that I'm keeping long term, I did a $1400 Mr.Shower Door assembly, thicker glass and frameless.  

Also thicker plywood.

I bought blinds this summer (I'm in Canada) and they have ones with thicker slats that they cut to size for free.

That's way thicker of a hole than I thought it'd be.

I ended up buying an actual wood transition piece since they were thicker which may solve your problem if you are only talking about 1/4 an inch. 

I usually will go with the higher end as they are much thicker and more durable and have never had issues with them.