The low interest rate environment since the great financial crisis lowered the valuation of the insurance float. If interest rates remain more normalized (think like 1995 to 2005), Float is way more valuable and thus BRK should trade at higher P/B ratios. 5% on the float sure is nice compared to near zero since 2009.

I'm not a big believer in this view.

It's the real interest rate that counts. Interest rates are higher, but inflation is higher too.

Plus, there is tax to pay on the NOMINAL interest earned, so there is actually a loss if both inflation and interest rates rise the same amount.

Year-on-year inflation rates don't tell the whole story easily--at the moment 12-month headline inflation is (unusually) lower than the 3- month T-bill rate--but overall I see no evidence that the interest rates being earned are sufficiently better in real terms than they were a couple of years ago to offer any improvement in the financial situation at Berkshire.
e.g., A portfolio of 3-month T-bills earned precisely nothing in real terms after 21% corporate tax from July 2022 to September 2023 while the T-bill rate averaged over 4.4%.
About the best you can say is that it hasn't been slowly losing real value they way it was for a couple of years before that.

The cash pile is worth a lot for sure, but nothing for its current real earnings. Only its purchasing power.

Jim