G.657B standard cables have a pulling (stress) bend radius of 5mm. So, you can abuse it quite a bit and it's fine. Also, while it is abused during installation, at rest, it is not under so much stress and usually have a sturdy casing to make sure it stays above its min bend radius.

I don't know if this is a helpful comparison for you, but my FTTH cable is almost identical size and material-wise to Apple EarPods cable. Has been working fine for years now, though obviously I don't move the router that much.

Most GPON is quite thin. Thinner and tougher than standard fiber patch cables.