Unlocking a summoner spell now costs a skill-point and maximum level has been increased to 20.
- Udyr could in theory opt-out of taking summoner spells to get all his skills to rank 5.
- You could go further and increase the maximum level to 22, and then have it so the bonus effects from masteries such as Summoner's Insight have to be purchased in-game - i.e. rank-1 Flash and rank-2 Flash.
- Experience gain or level curve would be altered so that you reach level 19-20 at the same time as you would currently reach level 18.
Alternatively, leave max-level at 18 and introduce "summoner points" that you gain at levels 1, 6, 11 and 16. Summoner points are functionally identical but independent to skill points - i.e. at level 1 you have 1 Summoner Point and 1 Skill Point. This allows junglers to take Smite at level 1, etc, and all champions can have both spells at level 6 (or opt to take rank-2 spell, instead).
I'm not saying things need to change or even that this idea isn't full of holes. There's obviously the issue with Smite on junglers, the power of junglers with access to an extra spell, etc. What if...