ZROZ
PIMCO 25+ Year Zero Coupon U.S. Treasury Index Exchange-Traded Fund
stock NYSE ETF

You're right. I'm thinking ZROZ isn't worth the hassle.

Citadel is going to shit the bed.
They are so far extended in 20 year treasury shorts. Watch $TLT (20-year) and $ZROZ (25 year +)
When the bond market begins to rumble shorts will be looking for the shrinking exit window.
Citadel is going to get pinched

If you're looking for convexity (that is, relatively cheap insurance that has potential for an outsized big payoff) I'd suggest long out-of-the-money SPX ratio put spreads. Here's one I had that paid off going into the Covid Crash. (When done right the carry cost is roughly 2% of the amount being bulletproofed against any loss whatsoever.) So another idea for your arsenal against big drawdowns is to consider maintaining an always-on tailhedge.
Back in my accumulating days I've also gone the route you're thinking of that uses high duration bonds. For that, I always started with the wish that, in the aftermath of an equity selloff, I want something in the portfolio to have appreciated by at least 5% so I could spend that 5% buying more stocks on the cheap. And that something was high-duration Treasurys.
But the duration needs to be super high for a small 10% bond stake to balloon into a 15% bond stake. An initial stake that small winds up committing you pretty much to using 100% STRIPS. Not diversified enough along maturities for my taste.
A 15% initial bond stake that could grow into 20% will require less duration, and can be achieved with a mix of 10-20yr maturities (VGLT) and 20+ maturities (ZROZ).
Me in your shoes? I'd want greater diversification among maturities for my high-duration stuff than what ZROZ alone could provide. And if you're interested in exploring tailhedging, you start reading here, which describes the basic structure of the put-spreads I like to use.
[https://www.fidelity.com/learning-center/investment-products/options/options-strategy-guide/1x2-ratio-volatility-spread-puts](https://www.fidelity.com/learning-center/investment-products/options/options-strategy-guide/1x2-ratio-volatility-spread-puts)
Good luck to you and all!
https://preview.redd.it/f349pyi5bpjg1.png?width=1228&format=png&auto=webp&s=49559253ea58924072b03d1aff5a38fe27dc7718

STRIPS: Comparing a 10% ZROZ "Convexity Hedge" vs. 85/15 Baseline for a $1M Portfolio