I plug my laptop (Arch Linux with GNOME) into a 4K 2x screen at home and 1x screen at work. All GTK apps just work — they adjust to the added or removed scaling. Electron apps don’t. They are either tiny or giant and must be restarted. 
Oh wow. All of the screens I use (laptop, desktop, phone, tablet) except my work one are HiDPI and I highly value the extra detail. My solution is to avoid apps that don’t handle it where possible. 