How? I cannot see how to read the width and I cannot see how to set width? I can fix the width but then the user cannot resize the columns. Are there any way to achieve this with any other components in SwiftUI?

The trick to set _forcedMaxZoomLevel no longer works on iOS 14. You get an exception that it is not KVO compliant. The trick with overlay tiles and canReplaceMapContent = true do work, though. I do not have a tilerenderer, I just need to zoom more for debugging purposes. So this is what I did: Initialization: let overlay = MKTileOverlay(urlTemplate: "http://localhost/{z}/{x}/{y}") overlay.canReplaceMapContent = true overlay.maximumZ = 30 mapView.addOverlay(overlay, level: .aboveLabels) _tileRenderer = MKTileOverlayRenderer(tileOverlay: overlay) and then in the MKMapViewDelegate: func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer I do return _tileRenderer There is probably a more elegant way to make a NOOP tile overlay than pointing to localhost but for debugging this seem to work. The maximum of 30 was just "big enough" to let med see differences on centimeter level.