I would take a general multivitamin every 3 days and on the other day supplement with targeted single supplements.
You NEED and must take daily a vitamin b12 supplement. Some foods are fortified in B12 but supplementing the food or supplementing directly is still supplementing, so do it directly.
Vitamin D especially in winter is important. When there is sunshine, you can put mushroom in direct sunlight and they will produce vitamin D, however in UK, sunlight is not always present
Iron is important for many cellular processes. Tea and coffee, even decaf , will drastically reduce iron absorption, so have your iron rich meal in the evening when you consume less tea/coffee. Add lemon juice to your lentils / greens
iodine in non vegan diet comes form the milk as iodine is used to sanitise milking machinery . Eat seaweed or take 3 drops of an iodine supplement.
Omega 3 are critically important for cognitive function. Supplement EPA-DHA with an algae source, not a plant source such as flaxseeds. ALA can be provided by flaxseeds so eat 30 gr of those daily as well. Check your Omega 3 supplement for EPA/DHA and not only ALA. Unless it is from a marine source, it is not good.
Selenium is very easy to obtain with diet with just 1 Brazil nut a day.
Zinc is easy to gain from pulses such as chickpeas, lentils, soya, ...
The complete protein is BS. All plants contains all of them, in various amounts, some plants are very low in a specific amino acid, other very high, but plants have all of them .
Spirulina has raised concerns for neurotoxins, and since there isn't really a reason to take it, I would be cautious.
Eat your nuts and seeds without overdoing as calorie dense.