It's better not to guess. The short answer is that you do not need to make any bias adjustments after a BHSE tube change, but it's worthwhile to measure with a multimeter just in case one of the new tubes is faulty or way out of spec. And wait at least 1 hour's warm up before measuring. There's a YouTube video about how to measure. For a longer answer, I've copy and pasted an old post below...
People here have used the term "bias" rather loosely to mean the balance and offset adjustments. But strictly speaking the bias is an internal adjustment set by Justin and which you can forget about unless (a) you really, really know what you are doing (i.e. a tube amp designer), or (b) you are recklessly stupid.
Of the external user adjustments, I don't think which is which has been formally stated, but I assume "balance" refers to the difference between + and -, and "offset" refers to + and ground. Both of these have the same "exponential curve" characteristic whereby they start off with a big difference at cold, initially quickly slide towards zero, the rate of progress reducing as zero approaches. Most of the slide has happened by 1 hour, but it continues sliding right up to 3 or 4 hours. As the Offset difference is an order or magnitude higher than Balance, its best to focus on that when measuring (the latter just needs an occasional check, but largely takes care of itself). The Offset adjustment is also more prone to a kind of hysteresis effect, i.e. nothing seems to happen as you turn the pot, then it suddenly overshoots. Even if you get it to zero now, it will probably drift a couple of volts tomorrow. This is all normal, but can keep OCD types amused for hours, or you can just not worry about a couple of volts..
The same applies to existing or new tubes. So there is no value in messing up Justin's original settings if you're putting in new tubes and adjusting after say 1 hour. All you need to do is use a voltmeter to check that the new tubes are following the same exponential curve. If at any time they are heading in the right direction, then leave them alone. Wait until the rate of change becomes insignificant, by which time you will find that the new tubes are magically close to the old ones. so no adjustment is needed. If the new tubes do not broadly follow the same curve, then there may, or may not, be a problem that needs further investigation.