User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:65.0) Gecko/20100101 Firefox/65.0 Waterfox/56.2.7
Steps to reproduce:
I tried to remove the blinding blinking cursors, so I could see if I've typed or mistyped something.
about:config does not include ui.caretBlinkTime unless users create it.
I copied and pasted the data from WF 56. I screwed up and ended up with ui.caretBlinkTime;0 integer 0 instead of ui.caretBlinkTime integer 0.
It's kinda hard to see what I've typed while blinded by that blinking cursor.
I then repeated but cut off the end, getting ui.caretBlinkTime integer 0.
But I was unable to delete ui.caretBlinkTime;0
As an accessibility feature, ui.caretBlinkTime ought to be included by default (and included in the front-end preferences).
Users should be able to rename or delete mistyped entries. So that users won't delete necessary values, maybe this should only apply to entries with no defalt value.