Remove automatic "ALL" option from checkbox list

[#1]

With New Work Experience and custom forms, checkbox seems to make it automatic to give an "ALL" option if there are more than 2 options for the field. We want to be able to not have the ALL option displayed at all as we find that users tick that box often when it is not what's needed.

[#2]

For those who happen across this idea, there is an older and more established version of this idea here: <Custom Forms> Ability to Disable 'Select All' for... - Adobe Experience League Community - 523050. Go vote for that one.