unable to choose from custom WHMCS integration template

This has something to do with the original question covered here:

https://wpmudev.com/forums/topic/no-option-for-portal-template-in-whmcs

Since the portal theme isn’t available, I’ve decided to create a customized Six theme that comes with WHMCS to fit my site.

As mentioned in the linked thread:

“However if you select automatic and select the theme in WHMCS this will use the default theme you selected there.”

I’ve selected my customized theme (named 6gs) in WHMCS and as instructed, in the integration I’ve chosen Automatic. However if I choose anything other than Six. I get the message: “Sorry this doesn’t look like a WHMCS site at [http://whmcs.gracesites.net/] Make sure your WHMCS Integration settings are pointing to the correct URL and that the WHMCS site is set for the Portal template in Setup | General.”

When I choose Six, it pulls the CSS files from the Six theme. I could edit the Six theme directly, but I would rather not as any changes I’ve made would be overwritten as soon as there is an update for WHMCS.

Are we going to get an update to the integration plugin that will include the custom themes that WHMCS supports?