improve handling of "or greater" speeds for jet arrivals

[mmp]

It would be nice to follow this general rule of thumb for jet arrivals to follow when they are issued a "or greater" speed:

5-10nm base/final 170kts
10-15nm base/final 190kts
15-20nm base/final 210kts
20+nm base to final 250kts

[mmp]

Also need to account for downwind aircraft with this, maybe take their distance to the field and double it and use that as the distance key?