Printing

The lesson on printing our of CLR was very informative. I'd like to suggest more. This is the comment I tried to post there but system wouldn't accept...

I have varying degrees of success with printing using a professional print company. They provide ICC profiles for the paper I choose, which I've imported into Photoshop. Fortunately, they allow me to get proofs for free; only postage is required. It can be an iterative process for each image. I wish there were a more efficient and predictive way of printing my images. I have an iMac monitor, Retina Display, that I've calibrated with a Calibrite tool. It helps, but sometimes, even after checking the Gamut warning, colors are off. I wonder if you have an interest in doing that one or two-day class for a fee, of course? I am thinking about upgrading to XDR. I wonder if that will help with predictability or just add more complexity.