my configuration:
Computer: MacBook Pro (15-inch, 2019); 2,3 GHz Intel Core i9; 32 GB 2400 MHz DDR4; Radeon Pro 560X 4 GB & Intel UHD Graphics 630 1536 MB
OS: 10.14.5 (18F203)
EN: Version 7.11 (457846 Direct), Editor: 69.1.8237 (1f0aea9)
I experience the lag in notes with pictures inside (one screenshot is enough to simulate lag). Notes without pictures works fine.
To simulate issue try to create few screenshots and paste it into note, maximise EN to fullscreen and than try to scroll -> on build-in retina display it is not smooth (on external non retina it is smooth)
i tried to disable automatic GPU switching and it doesn't helped. I also noticed high cpu usage during scrolling (goes up to 100% for evernote process)