I am by no means an expert on how these things are calculated but I do know there is a fixed limit to the amount of hive awarded based on curation. i.e. the rewards pool is a fixed size. Therefore, if you effectively increase the voting power at which everyone is voting then it will just take more voting power to be worth the same amount. In other words, I'm not sure this would result in much net change.
Also, in the long run, I'm not sure that is important that you consume all your voting power. If you simply don't allow it to reach 100% then I don't think you really lose out in terms of APR.
My understanding may be flawed but I don't think what you are asking for would really make much difference (if any) in terms of either vote value or earnings. Given that the rewards pool is a fixed size, I don't see how it could.
It is not my intention to affect earnings. The change does not let you vote more. It is hard to predict effect of something that might influence how people react to change, however my guess would be that there will be very slight shift of rewards towards regular posters at the expense of hbdstabilizer and other mana-burn content, since by letting people more freely allocate voting power to posts they actually want to support, they will be left with less excess mana to burn. It will also be easier to avoid reaching 100% and wasting mana regeneration.
After the change current behavior can still be achieved, f.e. if now you voted 100% for post A and then post B, after the change you'll still be able to vote 100% on A and 98% on B, getting exactly the same results. I doubt anyone will be willing to do that though. The change simply gives you more options on when and where to use mana you already have. After all users are (mostly) not bots, therefore they are constrained by things such as sleep, work, hobbies, social interactions and other entertainment - they are not slaves to Hive. Therefore the system should not artificially constrain users beyond clear necessity.