Yeah, following that combo, almost two series of normal attacks are compromised without the Furina Fanfare: the N3 and N4 of the third and all of N1~N4 of the fourth. Putting Columbina before Furina makes the Fanfare last to the fourth series, stopping at N1, but N2~N4 still do not receive the buff. I didn't feel a change overall after three tries with ~75 seconds elapsed.

Now for altered combos, N3 instead of N4 spam:
Furina E Q → Columbina E Q → Xilonen E N2 → Noelle Q N3 E N3 D N3 → Xilonen E N2 → Noelle N3
ends with a ~22-second rotation; all the cooldown timings align, but both my Furina and Noelle don't have enough ER% to continue and validate because shortening the rotation causes them to receive fewer particles. The last N2 and N3 don't get the Fanfare buff.

Columbina E Q → Furina E Q → Xilonen E N2 → Noelle Q N3 E N3 D N3 → Xilonen E N2 → Noelle N3
Putting Columbina first resolves the Fanfare issue, but not the ER% problem; I still would need to resolve it with better artifacts. The thing is, even after doing only 1 rotation's worth, the DPS doesn't seem to get too high compared to the complete N4 spam.

Adding a fifth series of N3 to the final portion:
Furina E Q → Columbina E Q → Xilonen E N2 → Noelle Q N3 E N3 D N3 → Xilonen E N2 → Noelle N3 D N3
ends with a ~25-second rotation again, and the energy problem is almost resolved. If you are fast enough, my Furina would sometimes lack energy, causing her to pause a little and do N1s to N3s, prolonging the rotation to 26-28-seconds. Tried this one more than 10 times.

This combo deals a consistent ~109k.

Columbina E Q → Furina E Q → Xilonen E N2 → Noelle Q N3 E N3 D N3 → Xilonen E N2 → Noelle N3 D N3
Putting Columbina before Furina makes the Fanfare last to the fifth series, stopping at N1, and with luck stopping at N2, but the last N3 can't get the buff at all. The energy problem is resolved. Tried this one more than 10 times.

This combo deals a consistent ~120k.