Photoshop CC 2019 unusably slow with large files
Hi. I frequently work with large .psbs 2 to 6 gb in size. The files are either ~10k pixels square with many layers, adjustment layers, smart objects, and blending modes, or ~20k pixels square with fewer, simpler layers. Since upgrading to CC 2019, the application is laggy/slow to the point of being unusable when working on these files. These same files are fine to work on in CC 2018, which is the only way I can continue to edit them now. I've tried fiddling with the performance settings but to no avail. Deleting preference files hasn't helped either. Is there any hope for me or am I stuck using CC 2018 in perpetuity?
Computer specs:
2017 Retina 5K iMac with 3.4 GHz Core i5 processor
16 GB 2400 MHz DDR4 RAM
Radeon Pro 570 Graphics Card with 4GB RAM
Mac OS 10.13.6
