Battery location

Getting to the stage where I am about to start the electrical on my KF 5 build. The manual calls for the battery on the inside of the firewall. The newer models are on the outside and I have seen a KF 5 on you tube with it on the outside. I think I would be able to mount it either way. Looking for thoughts/advice on this. Any pros or cons either way that anyone has run into? Right now I am probably going with an odyssey battery so weight would matter.

In theory the more weight forward of the CG the more you will be able to carry in the cargo area. YMMV
My battery (KF6) is located inside the cockpit and one day I will probably relocate it forward and move the voltage regulator inside.

If you can have it either location I would probably go for the engine side of the firewall. Shorter distance to starter and farther away from you if you have a battery melt down.