Tire Pressure Again

Believe it or not, I just thought of a tire pressure question that I have not seen discussed before. I usually check my TM pressure before I connect my TV. But since there is some weight transfer when the WDH is connected, I think it would be best to check all pressures after that is done. Is the weight transfer significant enough to make this an issue? Anxious for comments, as we leave for a week in beautiful San Diego's Mission Bay tomorrow. First time our TM has been out since February!