There are problems with the use of TIPS for the HBPP:
1. In a deflationary scenario, the principal value of TIPS declines. US savings bonds will not decline in value.
2. Accrued interest on TIPS is taxable. Interest on US savings bonds are tax deferred for up to 30 years.
3. STIP has a net expense ratio. US savings bonds do not.
4. STP is an ETF, which have an institutional manager risk. US savings bonds do not.
I have suggested the use savings bonds on this forum as an appropriate cash alternative-- or “Deep Cash” -- for those interested in their unique features and frequent higher yield. I still think they are. If they don’t fit your investment plans, you are certainly free to do without them.