[hatzie]

The disconnects on Transit Coaches are on the hot side of the 24v and sometimes, depending on the manufacturer, an additional disconnect on the hot side of the 12v output from the battery tray. I can't think of any that I've worked on in the last 28 years that had the disconnect on the negative side...
That's as close to industry standard as one could ask for since automobiles and pickups generally don't have OEM disconnects on the battery.

It would still be an issue on the negative side of the battery since the short to sheet metal defeats the purpose of the switch.

I used a switch duty 60A surface mount circuit breaker on the power feeds to the cab on my 76, since it's not a daily driver, and a the engine bay is full of retrofit 1998 & 1993 GM diesel engine tech. The remote starter solenoid next to the RH battery cuts off the hot wire along the oil pan, when the key isn't calling for engine crank, and the low current circuits are fed by an 8ga wire off the side terminal on the LH battery to a junction stud strip on the inner fender. It de-clutters the firewall and the starter BAT lug. Most everything is in the top of the engine bay. The fusible links are in easy reach without climbing under the truck. The alternator still has direct connections to the battery pair LH + has the charge wire RH + has the Sense wire.