For many years I'm a satisfied Mac C1 user (version 11 now). For fine-art printing I used QU and therefore had to export the to be printed file to a transfer-folder to QUltimate under Windows/VMWarefusion, it worked but was rather cumbersome. So I was happy to learn that Q1 was around which I'm using now.
There are two ways to transfer C1 files to external editors/programs.
1. Right click and use "edit with" and an intermediate file is generated. The "edit variant" selection window gives a number of options such as file type (jpeg, tiff and psd), ICC profile, resolution and the "open with program" (Q1)
2. Right click and use "open with" and the original file is passed through, in this case, Q1.
The direct invocation of Q1 v107 works fine. My workflow consists of using Affinity Photo for the impaint brush and making a border, so I end up with a TIFF file in C1. I use this file for the "copy with" variant. The advantage of using "copy with" opposed to "edit with" is that you don't end up with extra files in C1.
Make sure that you change History->Manage Disk Space->Delete files/folders older than: to 1 month because the Q1 export folder expands pretty fast.
I also had a problem with the reddish cast, after installation of Q1 the first print was reddish and the following prints were ok. I had to re-install Q1 from scratch an the same happened again. This behaviour remains a mystery for me.
For me Q1 shines for B&W prints.
Hope that this helps.
Hans
www.neecke.eu