I originally had dual balanced outputs on my pre, one set for my M60’s and one set to drive my Sub225’s directly ( through a parametric eq for bass management )
Going direct from the DS via the balanced out left me with little choice but to connect the Sub225’s directly via speaker level.
I lost my active bass management, but was able to realign and dial things back in to a point where the bass management was no longer needed.
Ultimately this was for the better sonically.
One of the items that I was considering to solve my single balanced output dilemma was the MSB Technology Sub Isolator.
It is a " Y " output connector that provides a dual output from a single balanced output.
One output half is straight out, the other output provides an isolated output for a sub connection.
This was a last resort option for me due to the listed price of $995.00, each I think.
But this may be the solution to your problem.
You may want to look into this item.