The 80 byte OP_RETURN limit is a relay standard, not a consensus rule. Nodes can set their own limit easily (-datacarriersize flag in Bitcoin Core). This means that nodes (including mining pools) are free to adjust their own relay limits on OP_RETURN size, if they want to be non-standard. tl;dr: You are free to make up your own byte limit but noone else has to "comply" with it.