Baseline (Widescreen) Solution & Issues
Edit conquest.ini in the installation folder.
Find "LimitResolutions = on" and change it to "LimitResolutions = off".
Voila instant widescreen bliss.
Ultra/Super-Wide (21:9/32:9) Specific Solution & Issues
Eyefinity / Surround Specific Solution & Issues
4k UHD Specific Solution & Issues