I think I have posted about this before but here goes again. Most installers will not take the time to "war-game" the location of any new equipment. They will usually find the nearest blank location on a bulkhead or deck-space and bang the item in place. The fact that you will have to remove the item later or else hire a member of "Cirque du Soleil" to service it, or the item behind it, is not their problem. And they are right, its your problem. Take your time locating new and replacement equipment, make mockups. The new inverter may have switches in a totally different location to the one its replacing.
So that's my excuse for taking so long to install the hot water tank. Most boats have it installed in the bilge area under the galley. I have batteries in that location. This is what I eventually came up with;
At least it will keep all the junk in the cockpit locker nice and toasty.