Audio Research VS110 Middle transformer gets very hot the 2 sides not so is this normal

$10 infrared sensing handheld electronic thermometer.

Point it at the transformer, on different areas of the transformer, and you’ll get a reading.

From this you can guess the transformer core temperature, as you are measuring it’s surface temp (which will be different). The numbers measured will be all over the place but will have an average.

This will tell you all you need to know, in order to get the answer you seem to be asking for.

That can be sort of true, yes.
But peace of mind is only a $10 electronic infrared thermometer away...

I expect to hear back a number of 50C or thereabouts. Not the exact correct number, as there never really is one - but simply a range, depending on the design.