My opinion is that adjusting anyone else's pc settings to match your designer settings is verboten - assuming you even can. Not only would you need to worry about ensuring you put them back to what they were (which means you first need to know what they are), there is no way you can stop them from switching apps, only for them to discover that things looked OK in Excel, but are messed up in every other app they switch to. When designing, you have to design for the norm, whatever that may be. I imagine it is possible with API's but you might also have to code for 32 bit vs 64 bit
When I was still working, 95-ish percent of people using my db's were using "normal" resolution of (IIRC) 1024x768. There were some hold-outs that were stuck in a rut so to speak, and still using 800x600 from the time of the dinosaurs. So they had a lot of scrolling to do.
I'd say that if you designed with 125% scale and most other users are using 100% scale then you made a mistake. I suppose you could have a disclaimer like "this file is best used at 125% scale in Windows Setting" but be prepared for backlash. Many will have no idea what that means, and don't want to go there. The biggest downfall, as I've suggested, is that the settings will apply to any application they look at, and that will include Outlook, Access, any web browser page, Excel, Word, etc. etc. I confess I cannot say for sure that I'm right about that but you could verify by seeing how other apps appear to you compared to before the update. Or you can make screen captures of the same window with different scale settings and compare those captures.