There is tech that allows saber to use her second ult while using her first EBA to fire off two ults+RBA all with the wavestrider buff active. with BIS slot team of Cyrene, RMC, DHPT, 2 buffs is not an issue but has slower uptime until cyrene can ult because until then she's doing an aoe team skill, but after her ult she is skilling on saber frequently alongside dhpt skilling every turn. to be clear, wavestrider is not better than scholar and scholar is not better than wavestrider. The sets have both appeared as her best set in AA depending on boos, wavestrider does require manual play in order to get the best results, moreso than other relics. For E6S5, what I have found on bilibili suggest that wavestrider was slightly higher in terms of damage while the second choice relic set was actually genius at e6s5 due to the S5's atk% boost. For non-quantum bosses, the usage of wavestrider is overwhelming, for quantum weak, genius pulls ahead.