In a nut shell as an instructor you cannot teach aerobatics for any useful purpose (other than fun) without lifting the restriction.
But the point is that you don't need an instructor rating to teach aerobatics in the first place! An FI rating is only required if you are giving instruction towards the issue or renewal of a licence or rating and there is no aerobatic rating.
I also re-iterate my previous point - the privileges of a JAA FI rating do not include aerobatic instruction so how can the CAA attempt to restrict a privilege that doesn't exist?
It states this in LASORS section H4.1.
LASORS has no validity in law - you need to refer to the ANO and the relevant parts of JAR-FCL. LASORS is merely a (rather poor) attempt to mimic the FAR/AIM - it is outdated and riddled with errors and mis-information, this issue being a prime example.