Good morning Whiff.
I had not heard of a drop diary before. A very good idea.
What form does the diary take please?
For examp;le, is it in an A5 notebook? Or what?
You might be doing this already, but, on thev basis of better knowing twice than not at all, are you noting date, time to the minute, for each entry. Also, are you individually signing each entry?
The best evidence is handwritten, signed and dated.
Also, try to leave a bit of a margin in case you, or an adviser, or the appeals panel, whoever, wants to photocopy the pages, as some photocopiers are a bit dim near the edges.
Are you including the details such as the stew onto your trousers and the floor?