SC2282 - variables starting with numbers aren't flagged as errors if done in arithmetic context

[RVC2020]

For bugs

• Rule Id: SC2282
• My shellcheck version (shellcheck --version or "online"): 0.10.0
• The rule's wiki page does not already cover this
• I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit

For new checks and feature suggestions

• https://www.shellcheck.net/ (i.e. the latest commit) currently gives no useful warnings about this
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

#!/bin/bash
((1num=1+2))
2num=$((10+1))

Here's what shellcheck currently says:

In test.sh line 3:
2num=$((10+1))
^------------^ SC2282 (error): Variable names can't start with numbers, so this is interpreted as a command.

Here's what I wanted or expected to see:

1num also be flagged as an error under SC2282,