percent symbol (%) currently not allowed in CIME namelist definition ids

There appear to be several SILHS namelist variable names (ids) that contain a percent symbol (%), as can be found in the "namelist_definition_cam.xml" file. For example, the namelist variable:

subcol_silhs_hmp2_ip_on_hmm2_ip_slope%rr

The problem is that the regular expression used in the CIME namelist scripts doesn't recognize the % symbol, and thus causes the namelist build to fail. There are two long-term solutions I can see to this problem:

1. Re-name the variable ids so that they don't contain a percent symbol, for example:

subcol_silhs_hmp2_ip_on_hmm2_ip_slope_rr

2. Modify the CIME regular expression to allow for percent (%) symbols.

Option 1 is the easiest on my end, but given that I haven't worked with SILHS at all I am not sure what impact it might have on that code, or if we want to have % symbols in namelist variables in the future.

Any thoughts or opinions?