To ensure I understand the proposal correctly:
The claim made in the OP is that the current phrasing of the FAQ can be misinterpreted to argue that two perpendicular temporal dimensions (i.e.: the 'time' dimension of two universes in a 2-C structure) validate a Low 1-C rating, based on the phrasing of the FAQ, when this is not the case by our standards. Therefore, the OP is suggesting rephrasing the FAQ to address this misinterpretation, and affirm that a second temporal dimension only qualifies for Low 1-C when it acts as snapshots of the first temporal dimension, thereby suggesting a 5-dimensional structure of a single continuum.
If I have misunderstood this proposal, then correct me. However, if this is what is being proposed, than I'd have to disagree simply because I don't believe the current phrasing of the proposal can be misinterpreted in this way in the first place - at least, not without an error on the part of the reader (in which case, anything can be misinterpreted, of course). To quote the current phrasing:
"This structure can then be generalized to any amounts of dimensions, and is also the reason destroying a spacetime continuum is a greater feat than destroying only the contents of the physical universe (Low 2-C, rather than 3-A or High 3-A). So, for example, a spacetime continuum comprising two temporal dimensions (Instead of just one) would have an additional time direction whose "snapshots" correspond to the whole of a 4-dimensional spacetime, and so on and so forth."
Note the use of the term 'spacetime continuum' here - not 'spacetime continuums'. A spacetime continuum with two temporal dimensions. This phrasing of the FAQ already stipulates that it only applies if a single continuum possesses two temporal dimensions. This term would not, for example, include reference to two temporal dimensions in parallel timelines - as those are two separate spacetime continuums, not a spacetime continuum. By the term in question being singular, it already establishes that it is not applicable when referencing parallel temporal dimensions.
Furthermore, the phrasing is indeed correct in this respect, at least with regard to how our tiering system functions. If a single spacetime continuum has three spatial dimensions and two temporal dimensions, than it is impossible to sort these dimensions in such a form that does not produce what we would refer to as 5-dimensional, or (in the case of tiering) a Low 1-C continuum. Therefore, the concern addressed over the way the phrasing can be misinterpreted is incorrect, and the phrasing is already in-line with what we would consider justification for a 5-dimensional continuum or a Low 1-C tiering.
Now, with this all said, there is a factor here I haven't acknowledged - namely, the fact that this whole discussion was started in the first place is some indication that the phrasing is not clear enough. Breaking down the semantics of an FAQ entry to explain why it is valid is not helpful if the kind of person who might need the FAQ to understand the tiering system wouldn't understand it in the first place. Evidently, that was recently the case with one of our threads. For that reason, I don't mind discussing how to rephrase the FAQ to reflect our goal of improved clarity. However, I admittedly think the current suggestion is needlessly verbose for this purpose. I honestly think just rewording 'spacetime continuum' into 'single spacetime continuum' to ensure the reader is clearly aware that it only applies to a singular instance and not multiple parallel instances would be enough to prevent further issues in the future.