This is the biggest issue for me as well, but I've mostly learnt to live with it by not scaling the HiDPI display in sway. What I do instead is scale the XWayla

This is the biggest issue for me as well, but I've mostly learnt to live with it by not scaling the HiDPI display in sway. What I do instead is scale the XWayland applications when possible. For me the only XWayland apps that I want to use on the HiDPI display are Chromium and VSCode and both of them have options for scaling (e.g.: "--force-device-scale-factor=2" for Chromium; "window.zoomLevel" for VSCode).