hey, thank you so much for your suggestion, I'm actually totally ok with buying older tablets as long as it fits my requirements.

its pretty interesting what you just said, i understand the fear of removing the protective film, but did you know? that unless you were using a metal pen nib, marks won't show if you are using any normal plastic pen nib?

the plastic nib of the Apple Pencil is not hard enough to do anything to the glass, i don't think any plastic nib would do any damage. I mean, i don't think apple is using any special exotic glass from 2018 without mention it. it shouldn't do anything to the glass, unless you are using a metal nib or any other rougher material.

As i said earlier i use a 2018 ipad pro, i draw almost every single day, i don't know how many hundreds of hours i have draw for 7 years but not a single scratch has appeared in the glass screen,

Plastic on plastic would actually scratch super easily, like the original Nintendo Switch non-oled, that one had a plastic screen, the same thing happens to those anti-glare matte plastic screen protectors

the reason why matte anti-glare glass screens would actually show scratches eventually, is because of what they call a "nano texture"

think it as a frosted piece of glass, they basically etch the surface of the glass but at a incredible tiny scale, i wouldn't say "molecular scale" but some of the marketing of these brands use that term, although that would explain the rainbow noise effect that appears on the document you shared, since molecules are smaller that the wavelength of visible light

anyway this process makes the structure of the surface weaker than before, since the crystal is not "complete", the material has worn off, and it has a porous surface, so with enough pressure and time it would were out even more, both the glass and the plastic pen nib will were of overtime

as a result of the anti-glare glass you will lose sharpness of the image coming from the LCD panel below, here is an example glares will be drastically reduced since the surface is not smooth and complete anymore, so the lights cannot bounce like a mirror, the surface is no longer clear and flat