Hi Lucie,
welcome on the ODK Community forum !
When you get a chance please take some time to introduce yourself here and explain the use you make of ODK 
I'll be glad to discuss about your workflow, as it seems to be quite similar to ours :
- input with ODK Collect
- Web visualization and editing with Lizmap
- Editing with QGIS (same qgs project as Lizmap)
- Datas are consolidated in a dedicated PostGIS database.
Farms are supposed to be visited a second time before the end of the project in order to evaluate the impact of the implemented actions. We plan to use entities for that second field sequence.
A private discussion or (best) a dedicated topic would be a better place to talk about it 