I'd keep an eye on that tube.....
Pulling one tube can effect the impedance of the output stage..... that is what the transformer "sees" as a load with one tube.
I know on the Stiletto Ace, it can be enough to increase the idle current significantly, and may result in more heat being dissipated by that one tube, even "redplating" in worst case.
If possible, measure the idle current, both with and without a tube on the other side.
And watch for any glowing on the plate of the remaining tube.
If idle current is reasonable, and you see no sign of 'redplating', then you are likely OK to run like this.
An example is my 50/50...it don't seem to care if there's a tube on both sides or not, but My Ace does not like it.
I've tried it with both amps and I find it's a little bit quieter and has more "grit" to the tone, but I prefer to leave them all in....
Good luck!