You won't be able to use more mana than you are today (that's why there is the need for an assertion to stop use of mana the user does not have). The system just won't punish you and your chosen author for not waiting for full regeneration after each vote.
You can only think about what deserves votes between posts you already read, not future ones, and current system affects the latter. Let's assume you read a lot of posts worth voting for and therefore you did vote. But the next day even more/better content appears. Too bad your manabar is still regenerating. You have the mana, but the system won't let you allocate it to the deserving post just because you lacked clairvoyance and you used a lot the day before. After the change you will be able to vote freely, and only in case you get reckless for couple of days in a row you will be stopped by lack of mana.
Now I'm heading to your post, because you've touched interesting subjects :o)
Oh, I see. You would have ten votes per day (if you vote all of them at 100%), and when you use all of them, you won't be able to vote, or the value will be greatly reduced.
I think that would be great because, as you mentioned, sometimes we vote for a post, and it gets great value, but then we see another post and will get less for a vote with the same %.
Today, I saw that the core devs mentioned this at the meeting, and even an issue was added to the GitLab.