I am surprised you are having 820 WOF spins because I was thinking mostly they are expired soon, but now I will recheck and try to have numbers like you, I have usually done after every week because once mine were expired, and then I never take any chance to go after few days.
There is no doubt I also like betting system which is good and fair enough with some good number of lotteries and rewards are also give extra bones for the users even I never have any referral but mine alone stats are mostly good and enjoyable for me now thinking to have few more things which will allow my chances better for winning more from here.
WoF from premium membership will never expire, you are free to play it whenever you want and the number 820 is not big even though it is quite a lot if our premium membership level is low because there are some members who even save up to thousands of WoF, and only WoF from email subscription has expired and only valid 48 hours after the email is sent.
If you choose to save WoF you will have the opportunity to get a smaller base prize because the BTC price since the beginning of the year until now has increased quite a lot, if you spin when the price is still low you will get a base prize of around 50 Satoshi/RP but when now is only half of it, and that's quite a loss in my opinion, but everyone has their own considerations.
I really appreciate your all this effort for giving all details about few things which were not in my knowledge now I can use better things with better way with this all and going for the increase in my investment with FUN token as well because I have feeling this is surely not bad at all because we can have many better things with this and site is also doing good job for the long time.
Here I agreed mostly WoF which came through email expired after 48 hours, but these are not having expiring date which is also good and thousands of WoF are surely having some good amount of the things as well.