Some more observations:
CHSN has started overlaying the pitch clock as an augmented reality graphic near the mound. As far as I know, they are the first to do this.
The Mariners will be airing 10 games on broadcast TV in Washington, Oregon, Montana, Idaho, Alaska, and Hawaii, with KING 5 as flagship.
https://www.mlb.com/press-release/mariners-king-5-tv-announce-six-state-list-of-telecast-affiliates
Speaking of Seattle, I've noticed that the Mariners' MLB Local Media productions (both this year and last year) frequently use a type of "panel" graphic above the scoreboard that appear to be completely unique to them, and have not been used by any other team. As much as I detest them for how dated they look, this is a detail that does make them stand out in terms of presentation.
I think I may have an explanation for them: the old ATTSN/Root graphics did similar "toasts". Given they maintain team-employed staff, it may have been added to replicate this functionality.