Train pass

According the DB German Rail Pass flyer, all GRP's are valid...

"...on DB-OeBB EuroCity trains to Kufstein, Innsbruck, Bolzano/Bozen, Trento, Verona, Bologna, Venice..."

https://www.bahn.com/en/view/mdb/bahnintern/international/redaktion_bahn.com/pdf-datein/pdf_2019/mdb_289891_grp-flyer_2019.pdf

This is confirmed at a second source - the Eurail-owned germanrailpasses.com website:

https://www.germanrailpasses.com/en/help/using-your-pass/which-trains-and-buses-outside-germany-german-rail-pass-valid

The GRP is valid on the other trains you mention in this area as well, but only for journeys within Germany (or from Germany to the border town of Salzburg.) Only the aforementioned EC trains can be used to Innsbruck after you cross the German/Austrian border.

I assume that the s bahn is included where it’s identified as part of the route?

No matter where you are in GERMANY, you can ride the S-Bahn.

Here's the Munich area S-Bahn. All routes are open to GRP holders:

https://en.wikipedia.org/wiki/Munich_S-Bahn#/media/File:Karte_der_S-Bahn_M%C3%BCnchen.png

Thank you again. I appreciate your thoughts

all GRP's are valid...

"...on DB-OeBB EuroCity trains to Kufstein, Innsbruck, Bolzano/Bozen, Trento, Verona, Bologna, Venice..."

That means the train must cross the border. The pass would not be valid for connections involving a Meridian train to Kufstein with a transfer to an Austrian RJ(X) from Kufstein to Innsbruck.

That's right - you have to catch the EC train within Germany. If you are coming up with an S-Bahn - to - EC connection at the DB site it's likely in München Ost where you change to the EC.