Yes, miners got a bit of a boost with credit on shares that should have been rejected, but that wasn't very fair to the pool or pw.
I disagree - I think the old system was quite fair.
Consider: the switcher decides to put half of the pool on tagcoin and half on litecoin. The miners on tagcoin will see much higher reject rates then those mining litecoin. Both are doing the same "real work" towards finding a block - but those rigs on tagcoin would be making a chunk less due to reject rate. Essentially, half of the pool would see lower profits.
Considering that we do not mine the smaller low-diff coins for very long, consider the more realistic situation where a chunk of the pool gets moved to tagcoin for a few shifts. That chunk is basically being "penalized" by higher rejects for a few rounds - possibly several percent difference in an hour of mining.
Please re-read PW's explanation of the difference between the way the previous stratum implementation and new stratum implementation works:
https://bitcointalk.org/index.php?topic=433634.msg5762701#msg5762701The pool was being overly forgiving in giving credit to shares that were actually stale after a coin switch. This means miners were being paid for shares that did NOT have corresponding profit for the pool to pay us with.
How was this fair again?
Your argument on low-diff coins and relative rejects between the two has absolutely nothing to do with what I was saying.
The way it works now is actually the way it should work.