What if you look up the specific non-Wyndham resorts I screenshotted above (Calypso Cay 3 nights with check-in on 29 Aug and Historic Powhatan 2 nights with check-in on 10 Sep) - are you saying that with your RCI points account those exchange fees are prorated?
Here goes.
I'll start with the Powhatan resort that's now a Hilton resort. The exchange fee for the 2 nights is $299 and 46,000 points! That's a lot of points for just two nights. Just to give a frame of reference a second tier 49,000 point one bedroom week at Vacation Village Grandview at Las Vegas has maintenance fees of $475. So that makes 46,000 points have a value of $445.91, round it up to $446 to make it easier to add everything up.
This F986 Powhatan has a $20.95 per day amenities fee and we'll call it $42 for the 2 days. It says the housekeeping fee is $100.19-$206.14. I'm guessing the lesser amount is likely a 1 bedroom unit and the larger amount a two bedroom. This reservation is for a 2 bedroom.
$446 maintenance fees on 46k points
$299 exchange fee
$206 housekeeping fee
$42 amenities fee for 2 days
$993 total cost for 2 nights
Powhatan #1045 only has full weeks. For for the week of September 6th or 7th it's 30,500 points for the full kitchen one bedroom. There's a two bedroom for September 5th or 6th for 41,500 points. The amenities fee is $25 per day.
$296 maintenance fees on 30,500 point
$402 maintenance fees on 41,500 points
$299 exchange fee
$175 amenties fee for the full week.
$770 total cost for the full week in a 1BR
$876 total cost for the full week in a 2BR
Here's where it gets really interesting those September 5, 6, and 7 weeks are available in Last Call Weeks. $319 for the 1 bedroom and $359 for the 2 bedroom plus tax, around $50, and the $175:amenities fee. $544/$584 That makes the 2 night stay an even worse deal.
I checked several other resorts in Williamsburg that offered less than 7 night stays. Three nights was the minimum number of nights on the ones I looked at but I didn't check them all to see if any gave the option for only 2 nights. The exchange fee for 3 nights was $139 and they were considerably less points than the 2 night Hilton Powhatan stay.
Calypso Cay has three different resort numbers.
CL1E - shows the option of 1-10 nights.
Exchange fees
$59 - 1 night
$79 - 2 nights
$139 - 3 nights
$209 - 4 nights
$249 - 5 nights
$269 - 6 nights
F381 - the only option is 3 nights with a $299 exchange fee
F383 - the only option is 5 nights with a $299 exchange fee
There's no housekeeping fee shown on any of the 3 resort numbers.
Club Sevilla #5169 is another Orlando resort that has less than 7 night stays with the same $59, $79, $209, $249, and $269 exchange fees. I know there are other resorts but RCI logged me out and that's my sign to go to bed.