The circuit a tube is used in is important.
Actually my findings are different to yours Mechans1.
I have 3 SP's and I find they respond well to tube rolling.
I use one of them with a pair of Grado SR325is for evaluating my tubes.
One of the SP's is a PPX3-6SN7 which uses 3 6SN7's both as driver and output.
Some noisy 6SN7's drivers became quiet when I use them as outputs.
The same can happen, but not always when I use a noisy tube in a different amp.