Check out the Adva MicroMux Nano for this use case if you
haven't already. 10x 1g in a single 10g transceiver using a
24S MPO. They also have a 10x 10g in a single QSFP28 as
well.
We tend to avoid such solutions because we are now introducing a
whole other device into the mix, which can be a problem when you are
talking about tons of devices across tons of PoP's. We rank it right
up there with media converters :-).
But certainly a solution to consider if it makes sense to you.