How about Marriott using a points based system similar to Hyatt, where you can convert your fixed week to points. With the points you would be able to do an internal Marriott Vacation Club trade and be able to book stays from 1 to 7 nights.
However, if you are a resale buyer you would only be able to do internal Marriott Vacation Club trades for a full week and would not be able to convert your fixed week to Marriott Vacation Club points.
Each owner whether weeks or points, or multiple week owners would have the same reservation window to book an internal exchange, or book their home week. The internal exchange would cost $39.
Marriott could use the week and unit that it shows on your deed as your fixed week that you would only have to call in, or use the website to confirm within a certain time period or that unit would be released for booking to other Marriott owners. If you wanted to book another week within your season at your resort, there would be another date that that would have to be done by. Either excepting your fixed week or booking another week within your season at your resort would be done at no cost.
If you are a weeks owner, you would still be able to book out of your season through Interval Interantional for an $89 exchange fee, but not through an internal exchange. When weeks owners did an internal exhchange they would only be able to book within their season or to a lower season.
Points owners would be able to book wherever their points would take them.
In addition, if Marriott exercised the ROFR on these units they would not be able to re-sell them as weeks that could be converted to Marriott Vacation Club points. They would have to re-sell them as regular weeks.
This would essentially leave the present system as it is, with the addition of a new internal trading system for weeks, and allow Marriott to ad a the new perk of a points based system without punishing resale buyers and sellers. This new Marriott Vacation Club points system would be a perk that would be an addition to the present perk of converting your week to Marriott Hotel points that are used for hotel stays, car rentals, and air fare.