For more information on the
Independent Force, consider some historical information online, including:
Gazette Website: PDF Navigator (and continuing through page 138).
Pioneer Pilot by Armstrong has a section on Armstrong's service as a day bomber pilot in 110 Squadron.
Noffsinger lists an unconfirmed book by Williams (55 Squadron) entitled "With the Rollo Fours" which looks like a memoir, but I haven't ever seen a copy.
Many units dropped bombs in addition to other duties. There are any number of books that may have accounts of bombing, just not with the four day bomber squadrons on the Independent Force.
Also, are you interested in bombing by seaplanes? The Cuxhaven Raid had bombing during the day - unsuccessful, sure, but bombing. R.D. Layman wrote a book about it.
No time to look further right now.
Dan