Glad you’re exploring this. Have you considered the Kindle Unlimited model? Basically, it’s mircopayments without the fee and overhead problem. Simple round-number version: subscribers pay, say, $10/month to read as much as they want from participating authors. All that money goes into a pool; let’s say this month is $1 million. Substack takes it’s cut; say 10% for $100k. The remainder is divided up among the authors; they get the same percentage of the pool as their readership. So if had 10% of the month’s reading, that’s $90k; and if had 2% that’s $18k. Or you could do it by email opens, subscribes…whatever you like.
Hope that helps!
Cjf