The other thing to keep in mind is that RCI's use of the term 'max TPUs' is a little loose. It means max for the moment you are looking at - not from now until check in date. What that means to us is that RCI can, will, and does change an assigned max value. So 'max' is not an absoulte value but one assigned at a given moment in time so depsoit percentages can be calculated.
Example (real life): max TPU is 26 for my high summer small studio on Cape Cod, depositing 18 months out. At 12 months out, max TPU is 24. I still get the 100% of the 24, but I also still miss out on 2 TPUs I could have gotten if I had deposited at 18 months.
So far RCI has made 'surprise' deposits of X number of TPUs when a max TPU increases over what was orginally given when an earlier deposit was made. I have received deposit credits of 1 and 2 TPUs a long time after I made a deposit. RCI has not made, to my knowledge, any formal statement or policy regarding these type of post-deposit adjustments. I think they are doing them to keep people depositing early - so there isn't an early deposit penalty. I think RCI remains mute on the topic so they can stop doing it at any time. Of course having people deposit early locks them into RCI, gives more time for more exchanges (revenue generation), keeps the exchange (and yes, rental) inventory fresh, etc.