I kept the receipts. CKPool post on the topic:

X (formerly Twitter)

Dr -ck (@ckpooldev) on X

Sub 1sat/vB transaction discussion and reversal of decision to mine them on solo ckpool. Block 910440 https://t.co/6WKLc4J07u is the first block t...

Mara Pool post on the topic:

X (formerly Twitter)

Portland.HODL (@PortlandHODL) on X

@MrHodl @reardencode @francispouliot_ MARA stopped because the additional risk of an orphan block costing 3.125 BTC is higher than the amount we wo...

You said they "noticed their blocks were getting orphaned" But neither of those two links said their blocks were getting orphaned. They just said they were taking steps to prevent the risk of orphaning

No idea. Have been mostly on stratum side of the house. But with slipstream, I imagine this would pose a similar risk so not sure why we ignore sub 1sat/vbyte.

Good point, I missed that