For the improvement adverse: Minimal change.
HFS-23-m-oldstyle.zip is available at
http://software.run.placeBuilt fresh from HFS2.3M original source, adding Leo's macro security patch, and the exec macro is disabled. Featuring the original defaults, the original default template, etc.... Not recommended for those new to HFS. But, HFS2.3m-oldstyle can help the "Don't Change" crowd to experience that in a real way.
For somewhat more comfort (optional) there is 'HFS 23 style template V2' included in the zip file. It is not preinstalled, but you could load it manually if you want to bypass some annoyances and run much faster (optional).
Edit: Also compatible with a pre-2025 hfs.ini file; if you happened to have an old backup handy from original M or K (remember to exit before copying the ini file to the same folder as hfs.exe). That would cause it to simply go back to work as expected.