LED indicator as night light?

I’m planning to buy a few red series dimmers. If I turned the LED indicator white and set it to full brightness would that provide any meaning full ‘night light’ functions in a totally dark hallway?

If your eyes are dark adapted yes I think it would work.

That said, if you have LED bulbs that work well with the Inovelli, it can dim VERY deeply and IMHO that’s a better option.
I have one in a hallway with such a bulb. The bulb minimum % to stay lit was like 12% so I set that in the Z-Wave minimum dim level parameter. That means a command of dim to 1% makes the dimmer start at 12%, so I get finer grained control of the output power level.
Point of this is- I set the config button to run a scene ‘nightlight mode’ that turn the dimmer on to 2%. That is just enough to start the LED bulb it’s connected to- and it puts out about the same amount of light as a very weak plug in night light. If viewed during the day the bulb looks like it’s off, but at night it provides just enough light to see where you’re going but not wake anyone up.

I hoping to have various LEDs and strips around the house, but I thought it could make a neat addition to have some of the switches be part of the ‘nightlight’ routine.

You could do it either way. Program a routine so at night, the LED color is set to white and the LED brightness when light is off is 100%. Then during the day, put both settings back the way they were.
Or just have the nightlight routine turn them all on to 1% or whatever…