In another thread, someone said that full schematics require NDA. https://bbs.bouffalolab.com/d/149-bl702-ble-rf-design-rules-and-recommendations/4
However, there are several BL702 designs (like the $3.50 SiPeed deubugger board) with very minimal overhead and that provide schematics. See https://github.com/sipeed/RV-Debugger-BL702/tree/main/hardware or another third party project at https://hackaday.io/project/180880-open-source-transparent-watch-t1/log/195809-schematic.
It seems I've seen additional schematics around for these, but I'm on a bunch of NDAs so maybe I signed off to partake of that very first offer. Or I "remember" a different or even unrelated board.
If you're looking to test "the whole machine" just inserting current probes on the 5VDC USB power rails is probably enough for coarse grade measurements, right?