Draw a couple of different arrow shapes. With some of them it is possible to modify the arrow tip with two modifiers (yellow points). Some shapes however provide just one modifier, others don't provide arrow tip modifiers at all.
expected result: all arrow tips can be modified with two modifiers.
Downstream bugreport with video:
Created attachment 142131 [details]
Video showing the behaviour
As the bug mentioned above is not public attaching the video showing the issue as you can see with some arrow shapes there are 2 modifiers, for some just 1... probably they should all allow the same behaviour.
The current collection is based on the set used in older Microsoft Office versions. Of cause we can improve our collection. But the missing handles are no bug, therefore I set this report to "enhancement".
LibreOffice has no UI to define or alter custom shapes, but you can define and alter shapes outside of LibreOffice. There exists some tutorials in internet.
I except this as enhancement request, because it would be nice to have handles for the corner arrow. In Microsoft Office you can alter the corresponding shape via handles, so it would be good for interoperability to have such handles too in LibreOffice.
Comparing the number of handles e.g. for the simple arrow, you have to consider in addition, whether the handles can only be moved top-down and left-right (Microsoft), or whether they are freely moveable (LibreOffice).