I don't know if we have seen the highs or not. But this talking head on youtube thinks we have not seen the peak
Reasons 4 and 5 are especially important to long-term yields as they assess the demand side of the equation. Quantitative tightening isn't ending any time soon.
If you want to follow along on what the Fed is doing WRT QT you can do so here:
https://www.federalreserve.gov/monetarypolicy/bst_recenttrends.htm
In terms of securities holdings you can interactively choose just that part of the fed balance sheet by clicking on the stuff you don't want to see below the graph. The Fed's security holdings peaked about 18 months ago at $8,505,586,000,000 and as Powell has stated have declined about $1T since then. The latest week showed total securities holdings of $7,412,483,000,000. That is still very high. During the QE program of the 2010s they never got much over $4.25T.
Another reason she might consider adding is that the average interest cycle once the trend changes is 22-27 years (see
https://advisor.visualcapitalist.com/us-interest-rates/ ). This does not mean longer dated Treasuries are going back to 15-16%. The next peak is likely to be much lower. What it does mean is that we are probably in for a choppy rise in rates into the mid-to-late late 2040s and what we have seen the past couple of weeks is merely a short-term retracement in rates. I don't know that for sure but that's my sense of what is going on.
So what's a treasury/CD investor to do? Laddering, or just spreading out maturities (
diversifying over time, if you will) seem wise since nobody knows for sure what will happen. Personally, I'm buying new issues between 8 weeks and 3 years for the most part, occasionally going longer. I buy in small chunks - about 2% of my fixed income allocation each time - so that if I'm "wrong" on any one issue it's no big deal. YMMV.