One thing I'll point out here, and it's related to magnification in general, is that it has its limits and they get hit relatively quickly.
For anyone who's had sight and used same for reading, we do not read letter by letter or even word by word, processing tends to take place in multi-word chunks at a time and we also possess a lot of predictive ability (and that applies regardless of reading modality) based on context.
I have had clients for whom magnification on a standard (and by standard I even mean large, but that would be used as a typical monitor) monitor needed to be boosted so much that by the time they could use the magnified version it robbed them of the needed linguistic context.
In this age of very large screen TVs, coupled with either HDMI output from the computer itself or casting ability (though the latter is more of a pain), it is well worth considering whether using a large screen TV as a monitor is the better way to go. The can be positioned such that they're where a monitor would be, if that proves to be preferable in the first place, and everything ends up magnified by default, preserving context. Even if you have to magnify some, a tiny bit of magnification for "the normal monitor" translates into quite a bit more when it's displayed on a big-screen TV. I learned all of this when I had to get creative with a client who had macular degeneration but who still wasn't ready to give up reading with her residual vision, and for whom no amount of magnification on "the small screen" produced a result that would allow that. We ended up putting her big screen TV on an articulating wall mount, which allowed her to pull it away from the wall and down when she needed to use it as a monitor.
Also a cheap UHD TV, which would be more than adequate for purpose, is far cheaper than most things in the world of accessibility are.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back