Apart from the issue that wires don't have properties, the other issue is that for this to work every node to node msg would trigger a websocket message to the browser, for simple flows this may be ok - but on more complex flows (of which we know there are many) and on low powered devices (of which we know there are even more) then the performance hit would not be insignificant. We already have instances where just the messages to the debug window can cause significant slowdown. Adding potentially hundreds (perhaps more) extra websocket messages is not something we are planning to entertain in the short/medium term. In settings you can turn on metrics and create a log with a lot more detailed timing information in it which you could then analyse, possibly in real time as a separate runtime, and could drive something like a heat map if so desired.
However that is the joy of open source - you can take and modify the code however you feel like. The main file that looks after the drawing is ./packages/node_modules/@node-red/editor-client/src/js/ui/view.js
Look forward to seeing what you come up with.