Yes. The only-3's-tempered size has some relevance here because you have generators that are fifths (or their octave equivalent or inversion). I overstated the case when I wrote that the untempered size was irrelevant. At least the
relative untempered sizes of the symbols are important. We try to avoid having any pairs of symbols whose size order in the temperament is the reverse of their untempered size order. If we can't avoid it we try to minimise their number and the amount by which they cross over (Trojan has a few). This is to try to preserve the feature of Sagittal whereby the visual size of the symbol is approximately proportional to the size of the alteration.
I'm sorry I don't wish to take the time I would need to spend to offer a valid opinion on your 3 options.
But the primary way of designing a Sagittal regular temperament notation is to decide what generator-count vectors you need symbols for, then take the prime count vectors for all the extreme resolution (Olympian) symbols (including those with mina and schisma accents) and apply your temperament's mapping to them (matrix times vector) to obtain the generator count vector corresponding to each one, to see which symbols correspond to the GC-vectors you need symbols for. You ignore octaves. Then consider whether you can drop accents. And consider the other things we've already mentioned like consistent flag arithmetic, double-shaft flags sequence recapitulating part of single-shaft flags sequence, minimising size order reversals.
See this thread:
viewtopic.php?f=6&t=530 It only gives rank-2 examples, but the same principles can be generalised to rank-3.
The commas for all the single-shaft extreme precision symbols (including those with accents) appear in quotient form in the above-linked JI Calculator spreadsheet. I'm sorry that it doesn't contain the vectors, but I expect you can compute the prime factorisations. Those are in a spreadsheet or text file somewhere. I just can't find it at the moment. Sorry. You can at least obtain the vectors for the unaccented symbols, from any of the "character map" spreadsheets linked from the Sagittal home page.
https://sagittal.org/