I am of the belief that this is the issue though. Your comment implies its unreasonable, my response suggests its the only arrangement any sane buyer would countenance.
No the sane buyer buys acl and the freehold, or just acl. or acl and agrees a price for a lease extension up to 99 years with the council.
The insane buyer asks to buy something that can't be sold and the insane poster posts in support of them.