I've had this modification on my pool all summer and I love it. It makes it really easy to install and remove the skimmer. I waited to post since I wanted to be sure it didn't put any stress on the pool wall.
I have a Hayward wall fitting that accepts the 1-1/4 threaded male to 1-1/2 female PVC adapter. I used 1-1/2 pipe and fittings and 1-1/4 to 1-1/2 adapter to the skimmer. I didn't glue the t fitting so I could adjust it and left it loose at the wall for removal.