yes you’re right… that’s the step ‘in between’
see howto 
1- download rtl8720_update.uf2http://files.seeedstudio.com/wiki/Wio-Terminal/res/rtl8720_update.uf2
2 - enter bootloader mode as described and drag file to external device named arduino, it wil reboot
3- start power shell command as mentioned before
good luck