Adobe Type Manager, Mac OS 8.5 and jagged/uneven fonts displays

One of the problems cited regarding Adobe Type Manager in Troubleshooting Mac OS 8.5 is the claim that: "it does not render screen fonts properly." Reader Thomas Piwowar believes this may be a more general issue, as noted in Adobe Tech Note #312465, entitled: "Troubleshooting Jagged Type 1 Font Appearance on the Macintosh." Especially relevant is the section dealing with situations where only some of your fonts appear jagged:

ATM cannot display a Type 1 font smoothly when the outline font file is not installed, when the font file or the Fonts folder is damaged, when ATM has an insufficient cache, when both the TrueType version and the Type 1 version of the font are installed, or when an earlier version of the font file is installed.

Each new version of ATM includes an updated rasterizer for rendering fonts to the screen. To work with a new version of ATM with an updated rasterizer, Type 1 fonts must adhere to the most recent Adobe Type 1 font specification. Some earlier Type 1 fonts do not adhere to the most recent version of the Type 1 font specification, causing them to appear jagged when you install a new version of ATM.

If you're using a new version of ATM, obtain an updated version of your font from the font's manufacturer to ensure it adheres to the latest Type 1 font specification.

Older versions of ATM (e.g., 3.x) do not require Type 1 fonts to adhere to the most recent Type 1 font specification, since the most recent Type 1 font specification was created after they were released.

The last paragraph suggests why upgrading to Mac OS 8.5 may precipitate the symptom, if it results in upgrading to a new version of ATM. Thomas had exactly this problem with several systems updated to 8.5 that were using out-of-date versions of Times and Helvetica. The main symptom was uneven spacing of letters rather than jagged letters. However, updating to newer versions of the fonts resolved the problem.