You can always use CSS to customize the look of the UI elements.
Examples
Customizing the marker icon size:
CSS
.open-user-map .leaflet-marker-icon:not(.marker-cluster) {
--icon_height: 41px; /* customize */
--icon_width: 26px; /* customize */
width: var(--icon_width) !important;
height: var(--icon_height) !important;
margin-top: calc(-1 * var(--icon_height)) !important;
margin-left: calc(var(--icon_width) / -2) !important;
}Depending on the size of your icon, be sure to change line 2 and line 3.
Secret tip:
You can even use animated GIFs as marker icons 🥳