X display max xy pixels

To date, after searching within Xlib, and more widely within Xenocara, I
have not found any reference that specifies e.g.: NUM_XY_PIXELS_MAX, for
the device's display.

The device's xy pixel numbers, are reported near the tail of a dmesg's
output, on arm64 and amd64 (and possibly others?).

Question 1.
Has my searching within Xenocara missed something relevant?

Question 2.
Is there a recommended/preferred method, to determine across all
supported architectures, the maximum number of a display's xy
pixels?

If you can provide relevant information I would appreciate your
response very much.


-- 
aer