Reference: Moving locations.
There are those that are set in their ways - I'm probably like that - who are happy in the location or grade they're in. However, some signallers wish to progress in their career. That is their choice, and fair credit to them for trying. In most cases it works out alright for them. I am aware of colleagues who stepped up to a considerably higher grade, only to find it didn't suit them. They've now found a position that suits them.
For my.own part, a number of years ago, my own role was facing some uncertainty. I applied for a higher grade resident signaller position, I was a relief at the time and still am. However, everyone I spoke to (wife, colleagues and also management) all asked if I would be settled in the chosen position. I had to be honest and say no. I don't regret not making that step, but equally if it hadn't worked out then my own circumstances may have been a lot different.
The important message here is believe in yourself, know what is achievable and what isn't, but take the opportunity if it suits. There will always be movement of signallers, and it's something management expect, to some extent. I've known management encourage their staff to apply for promotion.