there is a brightside at multiple injections per day it might allow for CGM

(less fingerpricks needed) worth asking that.
the one meal a day, have you worked out roughly the amount of carbs that is and let the DN know? 10 units. whats your current pre meal bloods and 2 hours after? it might be worth considering eating smaller dinner and having breakfast or something rather than a larger meal (if insulin based on larger meal and eating smaller that would likely need adjusted).
regards needles, the auto sheild duo ones i used are universal, my mums needles not safety ones fit both her pens. so would presume same
anyhow nice guidelines:
https://www.nice.org.uk/guidance/qs...itor-using-capillary-blood-glucose-monitoring will be useful if wishing to go down cgm route (some dont like the idea... i personally love using it). CGM could let u see what different foods have with impact on your glucose levels showing some foods to potentially avoid at same token show foods which your body tolerates a lot better alongside showing the spikes from meals. Personally i would ask about switching to possible carb counting. as if you eat eg 30g carbs one night for meal, then say another day its 80g carbs insulin requirements can be totally different.