I think this is down to the user. This has many perks including the layers on the hud widgets and scale of certain devices ie explosive device or scale on actual device like mutator ect
People who set rounds past 100 to as you gave in your example 100k are crazy like why would you even wanna do that. This is a useful perk that is used in a controlled manner by professional creators so i understand what your saying but also there is a ton of positives if its used in the same way.
ps This isnt a bug this has always been the case and i believe the limitation is there due to 1.0
Do not fix this