May I give you my thought on your question, have your tried on-line to the uk.border agency site and ask the questions you have for them?. Would the agency there in canada, be able get information for you, from their connections to uk. agency people? There are hand scanners for alternate scanning and checking you out and as you have a raft of paperwork to show them, maybe just stopping before the queue to scan and asking them there, as it is medical then they may well have a system ready in place. There must be other medical conditions which cannot be scanned.
Have you got some condition aware braclet/ around the neck alert items, which would show them quicker of your medical needs, things in pockets/wallets/bags are not easily found by other people if needed in a hurry. The details of your trips in August sound extremly tiring, so take it slow, and although you should not get jet lagged between NI and Scotland, your bs. may need extra monitoring, have a good and safe time, ttfn