I've seen references to 40 hours of the 125 hour FIC requirement being allowed as 'directed' or 'self' study. However, I can't find any mention of this in the regulations or guidance
The regulation states the minimum requirements for the course. In order to run such a course you need an approval and that in turn requires a Training Manual. An ATO will specify how they intend to conduct their course and what the 125 hours of theoretical training will consist of and how it will be presented. If that is accepted by the Regulatory Authority then thats what the course will consist of. Most courses include an element of self study or briefing preparation. You will only find this specified in the ATO Training Manual.
If the ATO wishes to conduct part of the course online, they would include that in the TM, whether the NAA accepts it is another matter. having conducted FIC training for a number of years I can't think of anything worse than trying to do the job online. I personally wouldn't do it, others might have different ideas.