Sounds like a mixed blessing there. I just picked up a stretchy hook and loop strap one for mine that I'll be reviewing soon. I was getting tired of swapping AAA batteries, and it fits my much bigger flashlights that take 18650 (and bigger) rechargeable lithium ion batteries
I don't think there's much of a standard, but there are definitely plenty of options. Here's a 1" x 9" strap pack amzn.to/3JRmY95 and a 1" x 6" strap pack amzn.to/4busbzj. Measure what fits and hack it your way!
If you can't reset on the device menu there is a manual way to. Disconnect the handset from power/network so it's off. Hold down the hash "#" key for the next few steps. Reconnect the power/network. When the first pair of LEDs turn on, release the hash key. Key in 123456789*0# and leave the handset to continue. This reboot may take some time. There will be no feedback on the device that it has been reset. You can reset the device from the Cisco Call Manager as well, if the device is communicating properly. Please note that this will remove any certificates installed on the device, so only reset in an environment where the device can connect to the switch directly.