Im positive they'll stick to manga as close as in seasons 1-3 so any big changes just shouldnt happen
However there are few cosmetic changes i'd like to see and they wouldnt really mess with the original material
-Give Mercury to kill FishEye. Every other Inner gets the kill beside Ami. There in no reason for that, she's strong enough and deserves the kill, Moon and Chibimoon can get rid of the Lemures.
-Give TigersEye more screen time. Almost his entire chapter and battle (?) with Rei is in his tiger form (similar thing happens with Makoto and HawkEye) which is rather disappointing. Just keep the human form for the most part.
-Give us some short but proper battles between Inners and Trio and Duo. In the manga its just Inners casting the spell, boom and done. Just give us something more (akin to Witches 5 battles)
-From the quartet its always PallaPalla and VesVes doing missions, JunJun and CereCete are just there doing nothing or stand in the background with random comments. Give PallaPalla command the FishEye mission, VesVes command the TigersEye one, JunJun the HawkEye one and CereCere the twins one. Also...
And give the Amazon Quartet some of the personalities they had in the 90's anime.
...yes to this. The quartet is literally one person all the time in the manga. Giving them some minor traits from their 90s anime personality (PallaPalla childish, CereCere feminine, JunJun tomboyish, VesVes bossy) would be cool from throwback standpoint and beneficial to the story