Panasonic has a patent for 18mm f/4 APS-C mirrorless lens (L-mount?):
https://photorumors.com/2019/01/31/...t-for-18mm-f-4-aps-c-mirrorless-lens-l-mount/
https://photorumors.com/2019/01/31/...t-for-18mm-f-4-aps-c-mirrorless-lens-l-mount/