There's definitely exploits to be had, like everything we've ever tried to do.
If I ran a weekly and it wasn't something that graded out to 100% TGP I would definitely migrate to a multi session league.
Take 4 weeklies of activity, grades out higher, submit results once so you pay less.
It cuts the endorsement fee down to $.25 per week for a given month instead of $1 per week.
Charity events are NOT exempt from this (and they have all known this for a while). They have the choice to play for WPPRs or not, and if they feel awarding WPPRs can lead to higher participation which can lead to more donations, that's on them to figure out.
The $20 per player charge for SCS Finals is still up in the air. Not knowing how this will play out we're likely to keep it for the 2018 season so we can "GUARANTEE" a bigger prize pool in every State.
Looking forward to the attrition rate. Approving 3500 calendar submissions and results submissions last year wasn't fun ... wait, I didn't actually do any of them (thanks @Vengeance)