Hello Rabbi - thank you for the detailed answer! Really appreciate it. Just to make sure I understood it right - I was talking about Mincha, for which we have a minyan at work. Based on what Im hearing from you, it is OK to start with Ashrei/Amidah before the kahal, in order to get to Chazan-led Amidah in time w/ everyone else? Again, thank you for taking time to respond!

ב"ה Shalom,, To clarify. I didn't realize you were talking about Mincha. I thought you were talking about Shacharit and you had just mentioned Ashrei as an example of what you have to rush through. What I said in my previous answer, that you must say Shmoneh Esrei with the minyan, I referred to the silent Shmoneh Esrei which is the main part of Tefilla. And takes precedence over listening to repetition of the Chazan-led Amidah. If you are talking about Mincha, you can always get a head start on Ashrei. But Shmoneh Esrei you MUST say with the minyan, that is the most important part of the Tefilla, even if the Chazan starts the repetition before you finish. You do NOT start your silent Shmoneh Esrei before the minyan does. If the Chazzan starts the repetition and says the Kedusha while you are in silent Shmoneh Esrei you may not answer, but you MAY stop where you are in your Shmoneh Esrei and you keep silent and listen to the Kedusha and it is as if you said Kedusha. (Shulchan Aruch Orach Chaim 104: 7 . Mishna Brura 28. If you need more clarifications, you can write again. All the best