Hi. I've been an avid user since I can't remember when.
I'm bringing up this suggestion, though perhaps it's been raised before.
Based on my usage, I'm suggesting or strongly recommending to make the 3D cursor (Q) and the cross-reference lines (Ctrl+F12) separate icons on the toolbar rather than nested within another function. I'll explain why.
E.g. in my case, the 3D cursor is assigned to the 6th mouse button. But when I press L or choose length, both left & 6th buttons shift to L. Again when I press Q to get the 3D cursor, now the left button also becomes Q, and I have to choose "scroll" again for the left button ... so it's a never-ending cycle.

Same with the cross-ref lines.. every time I turn off text annotations, the cross-ref goes away, and I've to find it & turn it on .. clumsy.

So I believe, making these 2 things independent functions & icons will increase ease of use significantly.
Thanks.