Pads on XBee3 and Logging?

Hello, I thought I had already posted this question but didn’t see it in the list sorry if repost…

I’m using XBee3 on an RTK GPS - primarily intended to send GPS correction data from a local NTRIP server. Lots of jargon! But it’s pretty simple, there are free services on the net to transmit GPS data that can be used to make your location more accurate, and there are mobile phone apps to send this data over serial. So, sending these corrections from an app via bluetooth to an XBee3, where those corrections will be passed along to the GPS. Now, the GPS uses those corrections to create a stream of more accurate GPS measurements, and I want to send them back and/or log them to a file for later massaging.

Couple of questions -

Can the XBee3 be used “bidirectionally” in this way - i.e. RX the correction data (handing it via hardwired serial to my GPS) and TX the corrected data coming back from the GPS somewhere else - maybe somehow back to the app, or maybe to a log somehow?

I’m hoping that the micro Python support on XBee3 might allow me to further massage the data (like time averaging some points, maybe trimming the log to the most interesting fields etc) and maybe forward that info back to a different set of RX/TX.

Then, I’m curious about those 8 pads on the back of the XBee modules - can something be soldered there (like an SD Card say, for logging? I haven’t found any documentation that tells what those pads are for.