Phal: In bloom, new leaf, and possible new spike.

[WhiteRabbit]

They can multi task
I just stick a skewer in the media, as close to the center as possible, to help me determine when to water. And you can watch the root color.
Many Phals don't miss a beat being repotted while in bloom, if you don't mess with the roots too much - but there's always a chance of bud or bloom drop - so it's up to you ...
I've had good luck using a skewer and watching root color, and waiting for the plant to finish blooming before repotting.