The information is not very valuable the next day, as you can't respond to it (until the next brew day but that is a very slow feedback process).
I would recommend a pH meter at home as a good investment. A field quality meter at home is more useful for mash pH than a lab quality meter 2 days later.
However, if I had access to a lab quality meter every day at work I would certainly use it to measure finished beer pH, probably on all of my beers (something I don't do now unless I suspect a problem).
ETA: I could guess at some factors that would affect pH stability, but not the magnitude of effect.
If I were you, I would mash a few ounces of grain in a travel coffee mug or something at work some day. Then you can get a pH reading during mashing and store samples for a couple days in a couple different ways and see empirically if any or all storage methods result in a stable pH.