Thanks atdre for the opening.
Especially true in the last year, we now have to use the web consoles in browsers and more modern tools and approaches as apps are running in the back-end and in the front-end only or mostly. We don't get that back and forth from the server and the client anymore - at least, less and less.
On this note, most of my processes needed to be "upgraded" and updated.
As such, I now most usually run recorded sessions with tools. One of this example is using the Burp recorder. In the last year it was greatly updated to enable the recording of web sessions and not only login sequences. Simply import.
This approach has the capacity for the tool to record a real user session (think selenium script) and then replay this session with the included data and "real-time" user and data flow.
Yeah, at some point you'll see a comm leave for a back-end server or API but most of the logic and processing has been done in the browser (input, validation, construction, rules, variables, etc.).
This now means that we can't rely on a "simple" proxy or plugin for interceptions, manipulation or similar. Again, maybe you'll see the occasional comms going out, but not like we used to see.
So my biggest recommendation at this moment is this. Record, replay and reuse (wash, rinse and repeat) and stick to that browser web console (check versions, variables, functions and rules). And trust me, it will take time to understand the app flow, certainly longer than a simple interception.
As most app I test - I don't know them. So I think the quick blackbox tests are a thing of the past. We now have to go much deeper in code and flow to get results.
Some links to help...