Applying the row filter requires an update of the Scheduler which is not possible during scrolling.
However, the latest sandbox build (2021.3.5048) now includes a new rowEmptyHeight property which lets you specify the height of a row without events. You can also set it per resource using resources[].emptyHeight.
If you set the value to 0, it will not skip the row like in the case of row filter but it will render it with zero height which will have the same effect.
You can download the latest version in the sandbox:
https://javascript.daypilot.org/sandbox/