Since no one cared to answer (at least didn't see one), allow me.
Heat sink - paranoia counter measure. There are two reasons to have HS in explorer build: multiple sun system and white dwarfs (dwarves?). If you drop into a trinary system where stars are really close to each other it feels like jumping into oven. Heat sink may give you extra time before starting to get damage. Same for dwarves. Tho I admit - that didn't happen't me for a long time. Few years later it was more common to get between two stars and suffer heat damage. Now it's almost non existent.
Double AFMU - contrary to common belief it's super handy for long range journeys that use neutron jumps. Each jump cause little damage to ALL internals. AFMU included. And AFMU can't repair itself. So as long as AFMU is operational you can repair the rest of the ship. When AFMU dies you're in deep biowaste. Unless you have 2nd AFMU to repair the main one. This auxilary AFMU doesn't have to be big, 2A will do - it's just for restoring main unit.
As for the OP - I cba what other people equip. I sometimes raise a brow at military bulkheads on explorer but then again - either L2P or intentional and if it suits the CMDR, who am I to argue.
Heat sinks are self inflicted these days as you will always enter a system in a safe zone, and not between stars, that hasn't happened for years.
Neutrons only hurt your FSD (unless you get into the EZ), and if your AMFU does get to 0% just reboot your ship and your AFMU will spring back into life and be able to repair your ship. but in any case you must have crashed into 50 or more EZ to start worrying about a low heath AMFU
although a 2nd AMFU is more forgivable as if its an empty slot, they dont weigh anything
Personally i stick a 2A in a class 4 slot, just because they're so powerfu and i really dont need a 4A, and refilling them isnt even expensive, cant even buy a single limpet for the same price! and i kinda like the loop of having to scavenge for raw mats while exploring to fix my ship.
