Existence of Windows version of Affinity programs makes running them on Linux theoretically possible. While installers refuse to work under both Wine and Mono, it's no big deal as it's possible to just copy the installation from another PC or virtual machine with Windows. However, after copying files the problem is usage of .NET and WPF while being 64 bit applications. Both Wine and Mono behave as if .NET is not installed. Support for 64-bit .NET on Wine and Mono is almost non-existent, however 32bit apps usually work. Therefore, 32bit build would be super useful, as it may mean finally getting professional graphic editor on Linux (of course there will be a lot of "fun" getting DX10 to work so nothing is warranted).
By the way, the only thing that made Designer go over 2GB of RAM usage was .psd exporting.