Looking for Aux circuit wiring inspiration (placement, location, etc)

I'm planning to add a secondary battery to my 2020 Tacoma, which as of right now is planned to be a seperate AUX circuit with the battery charged via a

$458 BCDC1225D REDARC 25A in-Vehicle DC to DC Charger with MPPT — Dual Input for Solar & Alternator Charging, Green Power Priority - 12 or 24V Battery Charger Suitable with AGM, Gel, Lithium LiFePO4 Batteries

BCDC1225D,

I'm trying to decide on a few things for the build and could use some inspiration by seeing what others have done or reccomend.
- Placement of Solar Panel Input (MC4) E.G. do people usually run a feed to the bed or just run the wires under the hood cowl when charging.
- What accessories to place on the secondary battery, and where to mount their plugs.
- I'm currently thinking of a dedicated 100a 2AWG circuit that branches to a female anderson plug and SAE connector (SAE for powering accessories like a fridge, light duty compressor), anderson for higher draw accessories like an inverter)
- I may also feed a WeBoost and my canopy dome light off this circuit.
- Switched accessories like lightbars, hood light, etc would remain wired to the start battery.
- Would a 3 position switch opposed to a 2 position one, allowing me to bypass the AUX battery and directly power accessories using the START battery/alternator in extreme cases be wise?

 

a lot of talk about it here https://www.tacomaworld.com/threads...ts-see-them-multiple-batteries-thread.295653/