Metal base acts as a heat sink with no increase in parts cost.
The 888D makes do without. Is it just a standoff for the transformer on the 888-non-D?
I don't understand why being an old thread is a cause to not post.
Yeah. I never understand posts that start with an apology for continuing an old thread, or complaints on doing so. Relevant information doesn't have an expiry date, and it's better than starting multiple threads on the same topic.