This only works if simaris-bought umbral mods come unranked. This is at least 3 days of rep grind from me finding out, and its for the grofit of 11% extra strength. If fiber doesn't come unranked, slot efficiency or range (line should let anything but overextended fit) or rank 5 Rolling Guard given it's likely more consistent than invuln-dashing with Vazarin (which only ignores magnetic when host).

Consider Arcanes: Nullifier vs Eidolonblast, Momentum for reload-slamming [Vectis Prime] or [Rage] for the extra damage, [Guardian] or Grace for survivability.

Full range of buffs mathed out below because as a cultured str meme I like it when number big.

Metronome Armor+ - 284.9% arbi, 179.9% GP+PB+EC+E, 160.3% EC+E, 142.8% E Only
Metronome Buff% 244.2% arbi, 154.2% GP+PB+EC+E, 137.7% EC+E, 122.4% E Only
Amp Multi - 16.28x arbi, 10.28x GP+PB+EC+E, 9.18x EC+E, 8.16x E Only

G A M E P L A Y
Because I queue pubs frequently, I take Vazarin. In teamcomp, feel free to bring Unairu or Madurai. Queueing like this is basically my call to any cry-for-help pub groups that need DPS or Support, because as with most of the starchart, Octavia does it all.
Lures? Invuln-dash to heal and protect from sky beams.
Shield damage? Outclassed by a volt shield, but any good amp (I'm partial to 777 and prism-draining) can do the job in a pinch.
DPS? Where Octavia shines, cast Empower after each Amp cast so it doesn't eat Energy Conversion and toss it somewhere convenient- bonus points if you can reuse it for multiple limbs, but as with most Hunters, you'll probably still be eating up lots of energy pizzas with this.

Outside of eidolon content? Stealth is still ludicrous stronk, but the -range on the build makes it a bit niche for use of 1/2 combo. Solution? Swap for [Stretch], probably. You can take off Empower if the content calls for it and you don't mind fiddling around some more, or put it on her 1 and retain the cc of her 2 to line enemies up for slaughter. Personal taste, really, I prefer the lockdown of her 1, combined with 4 the range isn't that piddling (assuming [Stretch] is swapped) and if enemies are shooting from outside of it, they're still distracted by it and making its damage soar, so no real harm done.