Shouldn’t you be able to do this using an interposing relay?

Typically used where low voltage triggers high voltage or vice-versa.

An interposing relay should just have dry contacts that close (or open) when you want to command the control coil to operate. Two different power levels can exist on an interposing relay with no influence on each other. Therefore no dim LED’s once you close in the contacts.

https://control.com/textbook/relay-control-systems/interposing-relays/ Ignore the overly complicated explanation in this linked article, but focus on how they show the DC relay on the PLC side (controlling device) connected to the relay coil which then closes the other circuit to the motor starter (your LED lights)