I often use the "Export for web" function, and the format I need most often is JPEG – arguably the most common format for images on the web. However, the default setting in Pixelmator Pro is PNG, and every time I use the dialog, I need to change it from PNG to JPEG.
I would expect the program to retain the latest setting I use, instead of reverting to PNG every time.
Is something not working like it should? Let us know.
I think that's a fair suggestion — I'll add that to the feature request list! In the meantime, if you find yourself always exporting to a particular format with the same settings, you can create a preset and then use the Share menu in the toolbar to export an image optimized with those settings without even having to open the Export for Web tool.