Yes, that appears to be a viable method. Just make sure that the N300IP is using the latest released firmware image.
Well that was scary, you reminded me to check so I triggered an update via the phone and it took AGES before the base station was available again. I thought it had bricked.
After all that, it just updated from 42.250 (422500000000 / V42.00) to 42.259 (422590000000 / V42.00).
Can't find the changelog for the N300IP but the N510IP says:
Release date:
July 2021
Released for Professional and Retail devices
Improvements:
XSI Broadsoft phonebook improvement
Support of new handsets
BugFixes:
Broadsoft CLIP/CNIP size
Other minor bugfixes ...
Disappointed to see it hasn't added IPv6 support which would surely bypass a lot of this hassle?