Running a backup (either manually or automatically) using the "openbackup-1.16.1-1.0.0.jar" version of the mod results in vastly overinflated backup sizes. I have attached a screenshot of the contents of the completed backup folder. The world is currently 251mb large, and the backup has so far reached 9gb and continues to grow.

The server is running forge-1.16.1-32.0.108.jar with the following mods installed:

BiomesOPlenty-1.16.1-11.0.0.393-universal
cloth-config-forge-4.0.2
collective-1.16.1-1.35
comforts-FORGE-1.16.1-3.0
doubledoors_1.16-2.1
durabilityViewer-1.16.1-forge32.0.38-1.8.3
excavation-1.5.1
extremeSoundMuffler-2.0.3_Forge-1.16.1
FastLeafDecay-v23
gravestone-1.16.1-1.0.6
jei-1.16.1-7.0.1.10
JustEnoughResources-1.16.1-0.11.1.93
light-overlay-5.4.2
MouseTweaks-2.13-mc1.16.1
openbackup-1.16.1-1.0.0
reap-1.16.1-1.0.2
ServerTabInfo-1.16.1-1.3.1
signedit-1.16.1-forge-1
StorageDrawers-1.16.1-8.0.0
TrashSlot_1.16.1-12.0.1
Xaeros_Minimap_20.20.1_Forge_1.16.1
XaerosWorldMap_1.10.1_Forge_1.16.1