It's always recommended to keep this extension in reserve just in case, for example, you go for an extension and find your funds have not seasoned for the full two months. It gives you the option of staying an extra 60 days rather than having to leave and start the Non-O process again.
a re-entry permit wouldn't mean another Visit Thai Family if one had been obtained previously on the initial Non-O or on one of the subsequent 12 month extensions. Effectively it is one per visa.
Those that say it is difficult are trying to steer you down the agent route which the majority of people do not use because, as you are finding, with the correct planning it can be done and you get the satisfaction of doing it yourself