Getting around pretty well so far but have a few suggestions I've noted so far as well as a significant bug in the print dialog. I'm able to work around it manually, but it happens each and every time.
1. There is no ready made canvas for 8.5x11" prints, nor is there a way to create or save custom canvases - this would be great as presently I need to manually create a canvas each time. I've set the default canvas to the required dimensions as a workaround so it is chosen whenever I create a new blank canvas but if I want to change the orientation, I have to manually type the values again, so it would save a lot of time (especially at an event) to have a "Letter" option.
2. The Tooltips are difficult to read on a full HD screen and are virtually impossible to read on a HiDPI display
3. In the print dialog, there should be a "Zoom to Fill" option as the "Fit" option leaves white space if the ration isn't 100% correct
4. Resizing screen - I see that CTRL-0 (on a PC) zooms the window to fill to the background, but I haven't found one yet that zooms (or unzooms) to the foreground. Does this exist? When importing some foreground images, they can be very large compared to a print sized background and it requires manually zooming out (with the mouse wheel or CTRL and + or - keys) to find the corner handles to manually drag the scale to match the canvas.
If you modify the print margins to any custom value, or select "None" and decide to switch back to default for any reason without shutting down the software and starting a fresh session, the default (assuming "auto") are reset to a value that results in a 0"x 0" image, requiring a manual intervention once again. If "Show Margins" is turned on, the entire preview window turns red.
There is lots to like, especially the speed. Good job overall and looking forward to the next release...