fte has some logic to extend coord sizes only if the map actually needs them.
this is auto-detected by checking if a map entity has an origin outside the +/- 4k range.
you can also force it with sv_bigcoords 0/1, if empty then it'll autodetect.
(using big coords results in eg ezquake or proquake failing to connect, so fte uses autodetection instead of just defaulting it to enabled).
dpp7 ALWAYS uses 'big coords', but if you've got dp configured to use protocol 15 or whatever then you'll get different results.
quakespasm can be configured to use protocol 999. this will also increase the map sizes (fte auto-forces the same protocol for nq clients when bigcoords are enabled).
the original protocol uses 13.3 fixed-point coords, giving 1/8th precision with +/- 4k range.
fte+dp both support floats for all coords (when configured to use extended protocols), which gives it the same range+precision as qc has.
999 has multiple options for extended precision, but you can generally assume that it supports maps at least 256 times the size.
the bsp29 format has a +/- 32k limit imposed by bounding boxes in the nodes+leafs.
DP ignores this completely, while FTE recalculates it if the map's geometry is also outside the +/- 32k limit.
2psb still has the same +/- 32k limit.
bsp2(the proper one) or q3bsp has no such limit.
finally, the far clip plane...
for fte, set gl_maxdist to 0 to use an infinite-depth projection matrix.
I don't remember the logic DP uses, I think its just infinite anyway.
quakespasm's gl_farclip defaults to 16k or something, but you should be able to boost it to fairly large numbers. beware of 16bit depth buffers.
also beware of skyboxes being drawn closer than the far clip plane limiting how far you can see.
note that if you have no entities outside the vanilla protocol's 4k boundaries, engines can still draw world geometry beyond that just fine, up to the map's boundary/far clip plane, if you like large vistas...
there may be other limits. I vaugely recall quakespasm having an issue with subdivisions if a sky/water surface is outside the +/- 9999 range. the qbsp is likely to also have limitations.