I was wondering if in 12.1.x are any additional changes to call blocking to prevent spam calls. I wrote in 10.x some additional changes and modified the SP's and table to allow to have company wide Black list. Which would allow a Admin add numbers which would be blocked Company / tenant wide. For now it was based on numbers only but I am thinking of moving to enhance to include Caller Names as well which would be matched via WildCard and RegEx.
Another change I am considering is instead of calling a stored procedure calling a restApi and then have a small service running to manage the different queries and then return a true or false to reject the call, maybe even allow to determine type of reject .