She've tweeted a while back that using anything other than Fantia isn't possible, so we'll have to wait for a good work-around.
It could be that Fantia restrict their users content while using their page, but I know she had her Fanbox running a while even after her Fantia, even if it wasn't getting updated. It's also possible that she doesn't consider it worth using another page, since she changed to Fantia previously beacuse her entire Fanbox was leaked all at once.
To be fair, she've had bizarre reactions to leaks in the past, like once she didn't post anything on Fantia for a week as "punishment" beacuse one of her followers had leaked her Fantia content, ignoring that the person in question was likely not even following her anymore, as the most recent leak of her Fantia content at that time was 3 months old, and nothing else had been leaked since then.