I should start with welcome to Wine Making Talk
One can make an acceptable tasting red wine with no metabisulphite. Tannin in grape skins acts as an antioxidant. Likewise tannic apples can make an acceptable cider or apple wine. My first step in trying to eliminate metabisulphite would be to include enough tannin such that on year one it wouldn’t be balanced, you would need some age on it for the tannins to polymerize/ become flavorless. Flavor wise, tannins and acids balance against sugar and alcohol (sweet flavors) so another answer would be design an early drinking sweet wine.
Building in shelf life is harder without having SO2, (active form of metabisulphite). You can improve acceptable flavor by running low pH as 3.0 to 3.3 and running high alcohol as 18%. The defect which I don’t like is acetaldehyde (from excess oxygen) limited oxygen will oxidize to a sherry/ nutty flavor which some folks like. A little acetaldehyde is normal and adds complexity/ a sharper dried apricot like flavor. The issue is above 20ppm when it can dominate the flavor. ,,, If the issue is sulphites and allergies note that yeast produce some sulphites which helps them kill off competitors, all wine will have a few ppm.
Ascorbic acid is fast reacting. As a result it doesn’t help a lot with shelf life. As Bryan noted ascorbic acid doesn’t kill bacteria so your risk of infection increases. I will differ with Bryan though, yes ascorbic is acidic but my guess is you would add ppm levels and not kill the flavor. ,,, We don’t have a good model of how ascorbic acid based home wine would be put together so this is trial by fire. The guess on my part is that starting with tannins and adding a few ppm ascorbic acid at each racking you could maintain taste and produce shelf life, ,,, especially if your crop/ equipment is clean so that infection risk is low.
As asked above, why skip the metabisulphite? The system works and is quite foolproof. If you have a reason then it is worth trying ONE batch.