Roller guide can be fine BUT it can also be a problem with using the bottom locations in the racking along the aisle.

Have you also thought about a wire guidance system?

Basically you have a slot cut in the floor down the middle of the aisle, feed the wire along this & then cover it with resin to protect it.

There is a small electrical box both ends of the wire connects to that provides the signal & also houses a back up battery in case of an electrical power failure.

You would also need to drill the holes for the in aisle magnets at each end of aisle & also the end of aisle safety magnets.

Both systems have different + & - points to think about.