Hmm, so I guess the real thing is you just want to document the maximum supported value? I think doing that in examples is not great actually. I would rather add a note to the description of the -h option in vt.8 describing the range of acceptable values and leave these examples alone unless they are describing invalid values (which the first example seems to be doing). So I would suggest dropping the change to rc.conf.5 entirely, tweaking the example in vt.8 to use a valid value and then add new text for the -h option to describe the range of accepted values.

Note that 16384 is not an intentionally set limit, it is just a consequence of an expression to ensure we don't have an integer overflow. It is somewhat conservative and could be made higher if there's a desire to do so.

Also the kernel returns EINVAL for values too large, but we could equally easily cap it at the maximum instead of rejecting values too high, if we want.