Holyrood Gait and the roundabout at the south end of it here (and similarly at nearby Queen's Drive) have sidewalk=both tags -- but they are also enclosed by neighbouring mapped highway=footway (and some highway=cycleway that implies foot=yes in the UK) ways.  Perhaps the sidewalk=both key on them could/should be replaced by sidewalk:both=separate ?

Ref: https://community.openstreetmap.org/t/separate-sidewalks-detecting-duplicate-of-existing-sidewalk-both/143120