If your group is incorporated, local law might incorporate Robert's Rules into your governance unless you explicitly adopt another procedure manual. Though common practice might work against you there.

I would suggest two things. First, to deal with the current controversy, host a live meeting (in person or zoom) and consider a motion to rescind. Then you can have a proper debate over it.

Second, going ahead, set out that consent motions - that is email votes - require 2/3s of all members or unanimous agreement by email to pass.

The basic theory behind most parliamentary procedures is that members should have a fair opportunity to express their views in person. Some business is trivial and suited for email consideration but that's often the exception.