Objects that are attached to NetworkIDs while in Syncmode (None) behave unexpectedly and increase the length of NetworkIDs unnecessarily.
There is a strange object that synchronizes even though it is supposed to be in SyncMode (None), I suspect this is the cause.
I'm using a SyncMode(None) Udons for locally behaviour. I noticed that a large number of objects were attached into VRC Scene Descriptor.NetWorkIDs. It contains a SyncMode(None) Udons. Although it is not always included, it seems that it may be included.
In any case, it is useless to have NetworkID when it only includes Syncmode (None) Udons.