(not sure whether this is still monitored, but posting anyways)
This would be a two-part adjustment
1) When taking over a new franchise, scouting and training budgets are reset to 10/10/10/10/10/10. At the beginning of each season, the maximum permitted adjustment is +/- 4. In order to allow for faster transition into the optimal budget model (maximum training, minimum adv scout), it would be a more satisfactory user experience to permit a per-season adjustment of +/- 5 instead of +/- 4 in each category. By doing so, it would only penalize a franchise-in-transition with one season of non-max training rather than two seasons. This would be better for the team as well as for the overall player pool in that world.
2) A secondary consideration would be allowing infinite budget INCREASE but only allowing the maximum decrease to be -5. So let's say a team is normally configured to sign a lot of free agents without losing any, and so their budget is normally set to Coll 5, HS 5, Adv 15. Let's say that team has a bad season or whatever and lets six type-A free agents to leave. The next season they could raise Coll and HS to 20, (but could only lower Adv to 10). Similarly, certain teams forgo medical budget in order to raise player. Circumstances could dictate a sudden need for medical, so that team should be permitted to raise from 0 to 20 in one step at the expense of something else such as player payroll, but should subsequently need three seasons to lower it back down to 0.
The theory behind this is that the extra half-step from 18 to 20 is redundant and requires an entire full season to accomplish, and this wasted time damages a franchise's entire depth chart for longer than necessary. When considered over time and across multiple franchises, this damages the overall player pool for a league and leads to greater imbalance between top teams with veteran owners and discourages owners from taking over rebuilds