Recording in 3440x1440 in HEVC at 60FPS is still not possible with Radeon Settings 19.7.1.
I'm certain I was able to do this before a driver update but I do not know which one.
System
Mobo: Gigabyte Aorus Master X570 BIOS F5g
CPU: Ryzen 9 3900X
GPU: Sapphire Vega 64 Nitro+ 11275-03-40G
RAM: 2x8GB DDR4 3600MHz
PSU: SeaSonic FOCUS Plus Platinum 850 W 80+ Platinum
Display: Asus MX34VQ 3440x1440 100Hz HDMI
OS: Windows 10 Pro 18362
Radeon Settings 19.7.1