We operate a large college testing center (250+ seats) and coordinate remote proctoring at a number of distant locations. Most of the exams we proctor are in Canvas. Entering passwords for every student's exam on the computers in our testing center is time-consuming, so we've recently asked our main-campus instructors to switch to IP address rather than access code for exam security. This works for a relatively small number of known IP addresses, but we've had to limit our use of this approach given the sheer number of potential IP addresses for online courses with remote proctors (even if we tracked these, the 255-character limit in the IP address field would stop us).
However, if Canvas first checked the IP address and then prompted for an access code only if the IP address wasn't on the whitelist, we could use this approach for all our exams and let us spend more of our time proctoring. (As I understand it, at present if both items have been specified, both are required.)