Victron mount. I had an irregular/square hole left over from the ex-Wallas control, so I got a $2 blank switchplate cover, made a round hole in it, and mounted the Victron BMV battery monitor there (just a quickie job in a campground prior to launching).
It's fairly handy where I have it (can operate it from aft dinette seat), but I may mount it up by the helm in future so I could also see it when underway. One reason I held off is that I didn't yet have trim tabs (then) or a windlass and so I knew I'd be putting other things up at the helm and wanted them to take priority arrangement. I did pick up a teak blank switchplate cover a while back, which I could use to cover the ex-Wallas-control hole if/when I move the Victron elsewhere.