ViewOptions.toURLValues sets incompatible group and group_level

Sync Gateway has a unit test that's issuing a view query with reduce=true and group_level=2. This works as expected using gocb v1, but in v2 it returns a query parse error:
"Query parameter `group_level` is not compatible with `group`"

It looks to me like the answer to the question posed here is "no", or at least "not if group_level is set".