IIRC, you have to use special flags when you compile from source to get HEIC support. And just because it's available doesn't mean you can legally use it. For example, the HEIF container's reference implementation is pretty explicit about not allowing commercial use [0]. The MPEG consortium lists over 7000 patents on their webpage for HEIC[1]. Making sure that you're bit infringing on those patents and/or working out a license deal with the patent cartel is a nontrivial amount of work.
I don't think you would be comfortable pushing this few-hours-hack to a system of such high importance. A mistake, be it stupid or complex, could break far more than the issue at hand does. And you would be at fault. Would you like to receive the response of all the students then? Would you really dare to risk this scenario?
That support depends on installing or building native libraries (mainly libheif I think) which is not trivial or may be that something developers can't do due to security reasons, also it's different for each platform.
