question

I have only bench tested my Orion smart, but...

How you want on powered is based on your system...my Orion will charge from the start battery to a LiFePO4 house bank. No switch (bridge installed) and it will have a parasitic load with the bluetooth portion and such (while it waits for an engine start voltage to be met)....a switch will shut it off, turning it on will do what it is then programmed to do (just as if the bridge was in).

@Philip M, with the remote bridge installed, the Orion-Tr Smart will not always be on, but will always be in automatic mode, which means it will turn on and start charging at the voltage threshold that you set - ie, if you set the "engine running detection" voltage to 13.6v, then the unit will turn on and start charging the house bank from the source bank when it detects a voltage at the source bank of 13.6v or higher.

If you wire a switch to the remote bridge instead of leaving the jumper wire installed, then the device will not start looking for the "turn on" voltage until you close the switch.

So: it's absolutely necessary for the remote bridge to be in place; whether you leave the jumper wire installed or instead wire a remote switch in its place is entirely up to you, depending upon your particular use-case. If you don't have any charge source other than the alternator at the source battery, then there's no particular harm in leaving the remote bridge with jumper installed, because the unit will not turn on until it sees your set voltage threshold at the source battery.

On the other hand, as some users have alternative charge sources such as solar or external chargers that top up their source battery, it may be desirable in that case to install a switch instead of leaving the jumper in place.