May be ChatGPT has the better Answer with CSS :
#sppb-addon-osm-86fddfe7-07df-43ca-85a2-fdb33b3f4c4c {
position: relative;
overflow: hidden;
}
#sppb-addon-osm-86fddfe7-07df-43ca-85a2-fdb33b3f4c4c .leaflet-map-pane {
margin-top: 100px;
margin-left: 100px;
width: calc(100% - 200px);
height: calc(100% - 200px);
}
This works for me.
Otherwise his first suggestion was to center the map on coordinates(unfortunatelly this didn't work with CSS), so may be you could implement this parameter into the add-on and make the configuration a lot easier for your users.
Thank you.