Many pilots over-rely on saying the minimum, iaw the "rules" in CAP 413 and say nothing more, even when it could improve the safety of the situation.
The way I see this is simple. CAP413 lists the standard radio calls so that standard announcements are as short and concise as possible. This leaves room on the airways for non-standard, more elaborate calls if and when required.
If you need to make a safety call but you don't know the CAP413 phrase for that, and as a result you keep silent, you're a muppet. IMHO.
Heck, there have been several situations already where ATC did not know the phraseology to use, so they switched to plain Dutch on me. If that's what's required to clear up a misunderstanding, then that's what's going to happen. Fine with me.