1. We can try a new definition:

Antipodal stars are stars which are rising 186 days later than those on the front side.

Applying this definition it is possible to state that Achird (η Cassiopejae) is the antipodal star of Regulus:

88 95 43
Ga4-5 (89) Ga4-6 (*154) Ga7-16 (*250) Ga7-17 (187)
Regulus (153.7) Antares (250.1)
230 = 90 + 96 + 44
35 152 52
Gb2-10 (266) Gb7-8 Gb7-9 (420)
autumn equinox Achird (11.7)
242 = 36 + 154 + 52
43 185
Ga2-13 Ga2-14 (45)
'Antares' (96 - 52 = 44)
230 = 44 + 186

Achird is another star than Regulus (Achir). And at Ga2-13--14 there should be another star than Antares, but I have put the name of this star as 'Antares' to indicate it is on the other side of the sky compared to Antares. If we could be certain that Antares was a name which means 'anti-Ares' we would be able to name this antipodal star as Ares.

Obviously we cannot find the antipodal stars by counting 186 glyphs ahead. The method to find them is not to add 186 to e.g. 90 (the glyph number at Regulus). Achird is at glyph number 420, i.e. 330 glyphs beyond Ga4-6.

But we can find the antipodal star of Regulus if we add 266 + 154 = 420 (Gb7-9). The reason is that 154 is the distance from glyph number 408 to Regulus:

63 88
Gb6-25 (408) Gb6-26 Ga4-5 (89) Ga4-6 (*154)
spring equinox (0h) 64 Regulus (153.7)
154
141 9
Gb2-10 (266) Gb6-25 Gb6-26 Gb7-8 Gb7-9 (420)
autumn equinox 142 10 Achird (11.7)
154

Spring equinox north of the equator is at Gb6-25 according to my model. But the creator of the G text could have had spring equinox (north of the equator) later among the glyphs. Precession moves the cardinal points 1 day earlier for every ca 72 years which is equivalent to say that the positions of the stars will move 1 day forward for every 72 years.

If the text is documenting where the prominent stars in the sky are located in relation to each other, then there is no obvious need to also point out where the cardinal points (solstices and equinoxes) at present are located among these stars. It should have been common knowledge and therefore unneccesary.

Furthermore, to document the positions of the cardinal points would lead to complications, for instance the necessity to define when in the day the observations of the stars should be done.

It is said (cfr Makemson) that south of the equator stars were generally watched in the early morning sky whereas north of the equator they were rather watched in the early night. If for instance someone on Easter Island saw Regulus rise in the morning and someone else on Hawaii half a year later saw Regulus set in the evening sky it would have been in spring in both cases.

Glyph 266 (the number for autumn equinox) could be meant to be at day number 266 counted from winter solstice on Easter Island. The design of Gb2-10, with toes at left (in the past) and a 'fin' in front suggests it is located in autumn (which agrees with the closed mouth of the fish). Spring equinox at Gb6-25, on the other hand, ought to refer to spring equinox north of the equator.

In order to avoid confusion we should not without special reasons try to connect cardinal points with glyphs, and a better way to present the text is to do it without them:

63 88
Gb6-25 (*0) Gb6-26 (409) Ga4-5 (89) Ga4-6 (*154)
64 Regulus (153.7)
154
141 9
Gb2-10 (#0) Gb6-25 Gb6-26 Gb7-8 (419) Gb7-9 (#154)
142 11 Achird (11.7)
154

Number #154 means 154 glyphs (days) beyond Gb2-10 and *154 means 154 glyphs (days) beyond Gb6-25.