There are a few things to consider.

• Are you using blazing pillage?

• Would your build gain anything from another aura?

• Are you willing to activate the power strength buffs from Madurai every 20 seconds?

I personally run a hybrid balefire charger blazing pillage build that uses corrosive projection to make up for the strength loss from overextended. That's the only time I can really justify skimping on strength, simply because of the mod capacity required to make the build function on a fundamental level. Otherwise, the rest of her kit genuinely gains a lot from having shitloads of strength.

Yes

...Radar maybe? if i run growing power im at 399% str, maybe 404% with another tau, allowing full strip of shields too

Nope

Updated numbers and posted build

You don't really need to full strip shields though (if anything it's handy to leave a bit of shield on stray enemies to refresh your own more easily), and as you said she doesn't really need a different aura. I don't think it's worth it.

What about swapping for umbral to allow for a different arcane and removing the need for 250 kills for full strip?

I've taken her to level cap in SP Circuit with basically just spamming Breach Surge and Blazing Pillage. A two cast build works just fine for me there and even in regular stuff like SP Defense.

Edit:

Low forma build I use for her most of the time.

Shards

I have over 1,000 hours in this game so far and I had no idea there was a Primed Redirection 😭

If you put corrosive projection on her you only need 328% ability strength

Remove Natural Talent and Fleeting Expertise (why would you even need this? Efficiency doesn't really matter, and if your shields are down, the shieldgate is enough to Regen shields for your next Pillage, or better yet with Rolling Guard). Put Umbral Intensify. 100+99(Blind Rage) =199+55(Transient Fortitude) = 254 + 44 (Umbral Intensify) = 298 + 30 (two Tau reds) = 328 + 60 (Molt Augmented) = 388 + 25 (Growing Power) = 413%. Add a single stretch mod so her 3 can target enemies further away. Put one Tau yellow or 2 normal for casting speed. Although if you instead put an Overextended, you now have 328% strength (Molt augment maxed) so you can instead just use Corrosive Projection. Now you have 190% range (good with a helminth like Elemental Ward and to extend the reach of your 3rd skill for Blazing Pillage)

This is my current build two Tau Reds for 30% ability strength, 2 Tau Reds for 30% ability duration to circumvent Transient Fortitude, 1 Tau yellow for casting speed. Molt Augmented and Arcane Aegis. You can opt for Overextended instead of Stretch and replace Growing Power with Corrosive Projection. This is more an endgame build hence Rolling Guard, but you can use Adaptation if you want. I just got day 400 today and forgot to slot in PSF. I use Elemental Ward as my helminth. You can also forego Molt Augmented if you get UI, BR, and TF with 30% strength shards at 328% strength with Corrosive Projection. Can replace the free arcane slot for anything else. And please use Arcane Aegis you will love it. You don't need much duration so no need to add Molt Efficiency there, unless you don't have the shards, in that case I recommend Molt Efficiency and Arcane Aegis.

I like corrosive projection for 2 key reasons. It saves a lot of strength, which is nice. But even better, by not actually fully stripping enemies you can reduce the chance of not having anything left in range to pillage, which helps her survivability a fair bit.