Custom/forced formatting would improve accuracy for people entering phone numbers, social security numbers, and case numbers with a specific format (Example: XX-X-XXXXX-XX).
Also when formatting numbers (eg. as ‘nn nnn nnn nnn’) the system will currently drops the 0 if that’s the first digit entered by the user. Usually there is good reason why that 0 digit has been entered and the 0 is necessary in the outputed document. There is a workaround in that you can choose tax field but then you can’t custom format what’s entered in the same way.