Using the parent case as a repro project, modifying a C# file will causing a domain reload, and out of that time 2-2.6s are spent inside of HDAdditionalCameraData.OnEnabled()

After deep profiling the issue, the code for InputRegistering.cs seems to be doing the bulk of the work, where calls to SerializedProperty.GetArrayElementAtIndex end up taking 2.6 seconds

Reproducible on Unity 2020.1.15f1:

1. Download project from here: https://drive.google.com/file/d/1O83GjyevXNPhSWlXtWTLJ96aU8A-Hmd1/view?usp=sharing and open it
2. Make a single C# change and profile
3. Notice that HDAdditionalCameraData.OnEnabled() takes at least 2 seconds

Note: I've attached screenshots of the profiler as well.

Relevant slack discussion: https://unity.slack.com/archives/C20E70CAC/p1611926333075400