Searches in DTTG list all versions of documents in my DT4 databases that are synced via WEBDAV. The databases’ properties have Versioning enabled but Audit Proof is not checked. Is this expected?
Audit-proof has nothing to do with DEVONthink To Go (and aren’t even support by it).
Please provide more concrete information when reporting issues, e.g., screen captures of DEVONthink and DEVONthink To Go, to show the effect you’re describing.
I was just mentioning the new database settings that I thought might be relevant.
Here is a screenshot of the document in DT4 on the Mac and screenshots of the relevant results from the All Text Documents smart group on DTTG. However, it looks like the versions don’t show up in normal searches, eg. if I search for “text Sunday”.
Ahh… now that’s very helpful indeed! 
@cgrunenberg and @eboehnisch: Behavior confirmed here in the global smart group in DEVONthink To Go 3.x.
Fixed for the next maintenance release.