On the forum someone asked if highway=services could be added to the polygons style.

https://forum.openstreetmap.org/viewtopic.php?pid=728618#p728618

For example like in the generic new maps:

landuse=retail | highway=services [0x08 resolution 22-20]

If added, prevent that it also will be mopped up by excluding it in the lines style

See https://github.com/ligfietser/mkgmap-style-sheets/commit/984b5ce9c8a9e9aacc61d0cd022e9768006408c9