Nomination Pools: Make permissionless withdrawing the default claiming permission

[ross]

I have recently posted a discussion around nomination pool claim permissions and how a change in the default reward claiming permission will promote the withdrawal of unclaimed rewards - now floating around 150k DOT on Polkadot.

In a nutshell, our original assumption of making reward claiming permissioned has turned out to be unintuitive for stakers, who do not expect to have to turn on permissionless claiming for alternatives - alas, less than 200 permissionless withdraws have been configured. Permissionless claiming is unknown and unintuitive for stakers.

To address this, we have prepared a PR to change the default pool claim permission to PermissionlessWithdraw, for all members. With this change, anyone can claim rewards for any pool member, similar to how anyone can claim validator payouts for nominators. However, members can still opt in to permissioned claiming via claim permissions if they choose - and I envisage this is an incredibly smaller demographic than the majority of pool members.

The PR also explored removing PermissionlessAll as a variant, but fell short of doing so due to the migration implications, that would require a MBM.

Posting here for any feedback or concerns the community may have of this change.

Cc @ankan @gpestana @kianenigma

[kianenigma]

Thank you Ross for sharing more details about this publicly.

As noted, this will change the default behavior for all existing members, so it is worth talking about it. We should expect any objection to be raised here.

I see no risk is changing the default behavior, and am in favor of it as it will improve the UX for majority of stakers. As noted, the few pool stakers who (for whatever reason) wish their rewards to remain unclaimed can always opt out of this system.