It could be nice to disable A record checking while adding mail domain like on mainstream panels (Cpanel, Plesk etc.) Because this logic forces to create A record on the migration process from another server. And it's not possible to change this record after adding (except manually editing postfixadmin sqlite file) if you define a temporary A record. But this is not always favoured. Because sometimes it is necessary to create all emails on the other server first for a smooth migration process.
In addition, this is also faulty if the domain has expired. Because in an expired domain, dns records are also changed. Naturally, when you want to add a new mail domain or just refresh the domain records on Mail Server plugin, it gives an error because the A record of the expired domain cannot be found. In this case, it is no longer possible to add a new domain or delete the old expired domain (except manually editing postfixadmin sqlite file).
In short, I find the A record check unnecessary when adding a mail domain. A well-intentioned logic added to ensure that the mails are actually transferred to the aaPanel. But the faults it brings with it are more than the advantages it offers.
Apart from this problem, I can say that aaPanel works as super as Cpanel in general. You are doing a really great job, I wish you continued success.