OP has finally started experimenting with pledge sorting, with FIFO trying it out in the first week. The longer you pledge, the higher your priority later on. It feels like it's moving toward fairness, but the 100k threshold is quite high.

Optimism mainnet announces experimental adjustments to transaction ordering rules, introducing a staking-based priority, and canceling the sole sorting standard based on the highest Gas fee.
The experiment lasts four weeks until June 23, and with approval from the governance body, participation requires staking ≥100,000 OP in the PolicyEngineStaking contract.
It is divided into two phases:
Week 1 uses FIFO, and staking amount does not affect priority;
Weeks 2-4 are weighted by staking duration, with longer staking leading to higher priority.
Participants who do not participate will still maintain the PGA mechanism.