The main advantage of the MoD is time saving, depending on what skills your generals have you can save up to 33% of your time on some adventures. However both General skills and 3x loots in events have made the MoD a less powerful tool.

Changing his round time will not turn him into a fast traveling version of the Tavern general if that's what you are after as his combat stats are different so we would still need to use different troop set ups on him.

Ask yourself why did BB give us a skill to decrease round times but not one to increase them.