Certain... things that have focus will display the mouse cursors I chose while others seem to go with the default (which looks like DMZ-White). For instance Firefox and Qt Creator will display the cursors I want, but when I mouse over Evolution the cursors used are default. What's even stranger is that some of the Gnome objects aren't consistent about this. The title bar shows the default cursors while the taskbar at the bottom shows mine. I thought it might be that I didn't have the vast wealth of redundancies in the naming of these cursors, so I compared the directories but didn't find anything important missing. Here's my listing:
$ l /usr/share/icons/MyCursors/cursors
total 176
drwxr-xr-x 2 pl pl 4096 May 3 15:54 .
drwxr-xr-x 3 pl pl 4096 Jun 5 14:27 ..
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 00000000000000020006000e7e9ffc3f -> left_ptr_watch
lrwxrwxrwx 1 pl pl 6 Apr 10 09:33 03b6e0fcb3499374a867c041f52298f0 -> circle
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 08e8e1c95fe2fc01f976f1e063a24ccd -> left_ptr_watch
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 3ecb610c1bf2410f44200f48c40d3599 -> left_ptr_watch
lrwxrwxrwx 1 pl pl 10 Apr 10 09:33 4498f0e0c1937ffe01fd06f973665830 -> closedhand
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 5c6cd98b3f3ebcb1f9c7f1c204630408 -> question_arrow
lrwxrwxrwx 1 pl pl 10 Apr 10 09:33 9081237383d90e509aa00f00170e968f -> closedhand
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 9d800788f1b08800ae810202380a0822 -> hand2
-rw-r--r-- 1 pl pl 4160 May 3 15:53 arrow
-rw-r--r-- 1 pl pl 33168 Apr 10 09:33 circle
-rw-r--r-- 1 pl pl 4160 Apr 10 09:33 closedhand
lrwxrwxrwx 1 pl pl 6 Apr 10 09:33 crossed_circle -> circle
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 d9ce0ab605698f320427677b458ad60b -> question_arrow
-rw-r--r-- 1 pl pl 4160 May 3 15:53 default
lrwxrwxrwx 1 pl pl 10 Apr 10 09:33 dnd-move -> closedhand
lrwxrwxrwx 1 pl pl 10 Apr 10 09:33 dnd-none -> closedhand
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 e29285e634086352946a0e7090d73106 -> hand2
lrwxrwxrwx 1 pl pl 10 Apr 10 09:33 fcf21c00b30f7e3f83fe0dfd12e71cff -> closedhand
lrwxrwxrwx 1 pl pl 6 Apr 10 09:33 forbidden -> circle
lrwxrwxrwx 1 pl pl 10 May 3 15:28 grabbing -> closedhand
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 half-busy -> left_ptr_watch
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 hand -> hand2
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 hand1 -> hand2
-rw-r--r-- 1 pl pl 4160 Apr 10 09:33 hand2
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 help -> question_arrow
-rw-r--r-- 1 pl pl 4160 Apr 10 09:33 left_ptr
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 left_ptr_help -> question_arrow
-rw-r--r-- 1 pl pl 16592 Apr 10 09:33 left_ptr_watch
lrwxrwxrwx 1 pl pl 10 Apr 10 09:33 move -> closedhand
lrwxrwxrwx 1 pl pl 6 Apr 10 09:33 no-drop -> circle
lrwxrwxrwx 1 pl pl 6 Apr 10 09:33 not-allowed -> circle
-rw-r--r-- 1 pl pl 4160 Apr 10 09:33 openhand
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 pointer -> hand2
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 pointing_hand -> hand2
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 progress -> left_ptr_watch
-rw-r--r-- 1 pl pl 45600 Apr 10 09:33 question_arrow
-rw-r--r-- 1 pl pl 4160 May 3 15:54 top_left_arrow
lrwxrwxrwx 1 pl pl 5 Apr 10 09:33 wait -> watch
-rw-r--r-- 1 pl pl 4160 Apr 10 09:33 watch
lrwxrwxrwx 1 pl pl 14 Apr 10 09:33 whats_this -> question_arrow
The only things I see missing there are things that are not part for the main pointer. I set this up through Tweaks. Yes, I have logged out and restarted.
I'm running Ubuntu 18.04.02.