Ok so I looked at the shop manual and still don't know if you check the fluid level hot or cold. All it says is while on the kickstand with the dipstick o-ring just touching the transmission housing, not tightened down. TIA

 

Its always best to check fluid levels when at operating temperature. (Hot)

Watch this youtube clip.
What you are asking about starts at 2mins 45sec. Its a Dyna, but its the same method.

This is how you would check for a 2016 FLHXS.

 

What year and model is your bike ?????

The reason I ask ,, earlier models your screwed the trans dipstick in, till just touching the oring for oil level check ...
Later models , you do as in the video, (not screwed in, just touching the threads )....

When the change over happened ,, many thought they were over full checking their new later model bikes without looking at changes in their new owners/service manual...

I nearly got caught out , as I had a 2009 electra glide at the time, (screw into to check tran level),, and then bought a 2015 street glide, (not screw in to check tran level).....

 

Tranny fluid level does not make any difference whether hot or cold.. Engine does.. If you are worried about the leakage issues. do it at the same temp.

 

The fluid levels are also addressed in your owners manual, where there may be more useful words. As Max points out, hot or cold won't make any difference for the tranny oil - it can't go anywhere else, but if it does there will be a lot of mess!