Describe the solution you'd like
Global modifiers for XP gain. All-skill and per-skill.

Why is this feature needed
Sometimes the ratios got reqs and XP gain are right but the pace is too slow. Modifiers allow for a scale on XP gain without needing to change XP values.

Describe alternatives you've considered
Make players edit every setting of every item to scale down the XP.

Additional context
This was a legacy feature and should be reimplemented.