Am I assuming right that your setup was encouraged by my 1Writer workflow I mentioned in the DTTG and Files integration thread?
If so I have to add that I use 1Writer and DTTG primarily to get stuff into DEVONthink on the Mac. I have never centered my work around DTTG. This might change at least a bit though because DTTG 3, including its way more reliable CloudKit sync, might actually, as someone has put it in these forums, be a game changer for me too.
Anyhow, I have never used the combination of 1Writer and the DT products in full circle like: 1Writer on iPhone/iPad → iCloud Drive folder → indexed by DT on the Mac → synced to DTTG on (the same) iPhone/iPad.