Certain models have lift up cistern doors, flaps or removable dynamic brake blisters to facilitate charging & on/off/charging switch. There are ways to angle mount charging ports and the use of a push button for indistinct availability. Other ways to reduce the presence of a switch and port would be to mount them in fuel tanks or hang them from car floors. A little flat black does wonders.
Sometimes you just need to mull your targets. If your interest is model perfection then there will be limits. if your interest is the fluid operation of trains irrespective of layout wires, dirty track, wiring complicated switches and diamonds then a bump or port here or there just becomes a real big "so what!"
Many locomotives today have hidden access which could be repurposed.
It is a subjective matter. If it is a problem, then maybe the freedom of battery R/C is not for some folks.
I have a couple of Lionel's 2-6-6-2 engines in two rail as shown. I just took some brass stock, calculated the space needed for the toggle switch, bent it into a pair of legs and feet then screwed it to the tender floor and presto, switch and port is hidden and serviceable.
Where there is a will there is a way. Bob Buck is a master at hiding switches and ports.