Low level debug or free memory on wio terminal

Ah, I understand. At the moment I only remember how to get logging messages from the WiFi libraries, see this link:
-rpcWiFi library only working intermittently

// Memory usage Wio Terminal
// 20000000 First 64 K Ram Block
// 2000FFFF
// 20010000 Second 64 K Ram Block
// 2001FFFF
// 20020000 Third 64 K Ram Block
// 2002FFFF

// Heap goes upwards from about 2000A4A0 (in my application)
// Stack goes downwards from 2000FFFF

In one of my applications I had not enough stack, so I put some larger buffers in the not used third 64 K Ram block