We have seen previously potential subscribers who were frustrated because their free webhosting didn't include the ability to put files in .well-known/ so they couldn't pass http-01 for that reason. Under your "maximum issuance" approach doubtless you would let them put the response somewhere else?
We have seen people who couldn't figure out how to change the MIME type response to match what is required by ACME and so struggled with http-01 for that reason. Presumably again you would just remove this rule so that they can more easily get their certificate ?
As pfg has written "maximum possibilities for cert issuing" cannot be the rule at the expense of practical security. You could change your DNS arrangements to make dns-01 practical, you could choose a server that can pass tls-sni-01 but you've chosen instead to insist that http-01 requirements should be weakened. Any fix to cope with the "bad default HTTPS" behaviour we see in the wild is going to require the same sort of features as tls-sni-01, which already exists, so it's redundant.