The main point of Kaheera is that it allows you to free roll a 1x FoV in the board regardless of your colors; just pay whenever you're in the mood to 2-for-1. More of a RiP/Helm type of tactic though.

At some point you're going to have to choose between Cast Out with Replenish or no Replenish at all or red splash with 1-2x Burning Wish/SB Blasts + 1x Replenish in SB. The deck is a little too slow around the 3 mana mark; while it may cast a 3cmc spell it's not really able to get ahead and leave something that the opponent has to deal with (your Teferi lacks a [-3] Astrolabe, Thirst just draws and will rarely find 2 things to good enough to bin right into untap Replenish, and Dovin's Acuity kinda just sits there). The moment they challenge Shark'nado (which can be as simple as Cling to Dust) you're going to struggle to recover any ground with Replenish.

While Cast Out is a pretty dubious card, it's kind of mandatory with Replenish...and you're throwing away your SnT matchup without it (and getting worse vs REB and Veil at the same time). On E Tutor, it cycles now, and you get to choose between Astrolabe [fewer mulls, combo with Teferi] and being a 5th copy of Shark'nado. Ponder isn't going to draw you into better plans with Replenish in the mix; you're falling behind by stopping to cast it when it could have been a mana-fixing, consistency positive combo piece. You don't want to sit there at the 3-5 mana point sinkhole'ing a mana [back into Daze range] to Ponder when you should be directly pursuing a way to win. The planning phase was many turns before this point, and you have combo pieces able to do all the heavy lifting early by making sure the mana development stayed on pace [even if the opening mana was white] without de-railing the train. It all comes back to Replenish; if you're going to do it, you really have to hit the gas pedal.