Investigate MaxPartitionsPerPoStMessage boundaries

[rjan90]

User Story

FIP-0070 has nown been accepted, and is being included in the nv21 upgrade. After the network upgrade it is expected that storage providers will move partitions across deadlines and create "business hours" where they are proving their sectors/partitions, and "maintenance hours" where its easier to do maintenance without having to do proving.

With this change it is expected that we will see consollidation of partitions and that users will have an increasing amount of partitions in a deadline.

Most Lotus user have not been anywhere near the MaxPartitionsPerPoStMessage limit (10) today due to other blockers, but with parallel windowPoSt computation/gasfee cap enhancements landing, users should be unblocked to have a high amount of partitions in a deadline.:

• feat: wdpost: Parallel wdpost batch processing #9615
• feat: mpool/wdpost: Maximize feecap config #9746

In anticipation of more partitions in deadlines we should investigate if there are risks of exceeding the BlockLimit when MaxPartitionsPerPoStMessage is moving towards 10. And if that is the case, we need to find out how we can deal with it, either by 1. Lower default towards a more sane value or 2. Automatically split these messages when approaching the BlockLimit.

Acceptance Criteria

• Create a report to see if there is a risk of exceeding the BlockLimit when MaxPartitionsPerPoStMessage is moving towards 10 partitions. We should investigate this for both non optimistically and optimistically PoSts.

[rjan90]

Closing, since MaxPartitionsPerPoStMessage is now 3 - which should alliviate concerns that one will exceed the BlockLimit when MaxPartitionsPerPoStMessage is moving towards 10 (the previous limit).