For long term results I would suggest that the answer is to eat what gets you normal blood sugars, energy, vitality, health and strength consistently; anything else, will not be long term.
When you say you eat junk food Vegan, you already know the answer to that point consciously, so you need to convert the sentiment to actions that work for someone who is carbohydrate intolerant.
I accept beetroot, butternut squash, carrots and berries into my LCK regime. I understand that my HbA1c may not be low 30's, so take the mid 30's. It is not likely the a WFPB approach for example with root vegetables will get you the numbers you seek, so within the parameters you have selected, I would suggest being frank about the foods on your protocol that will work.
Yesterday I listened to Dr Gabrielle Lyons. She is on the meat side of things, but is true expert on protein. She stated that muscle can provide up 60% of glucose disposal - this has got to be applicable to Vegans also, so maybe Power Building would help you.