I think 17a is just an anagram (What might be re-presented as) of the initial letters (Anticipating bits) of the remainder, with the definition being the whole clue, so &lit. I thought it was very clever and original.
Hi Jono,
Late to the party this week but still can't parse my last clue (3D) despite your helpful advice.
Is there any steer as to which two letters are to be inserted and does that give me a fish or something else?
A bit dense this week.