Well it’s really a business decision to use these older and more archaic products. The decision essentially boils down the to cost of using that piece of software (Cost of supporting an old piece of software, cost of it not being as highly available as it should be, cost of not being able to offer the latest features to your customers, etc) vs the cost of using something different (Cost of buying new licenses, cost of developing bespoke software, cost of the risk of changing software vendor, etc). Ultimately by deciding to use or start with these older products, the decision has been made that availability is not as critical as some other factors and that some downtime every so often is acceptable. Of course if this is not the case then I’d suggest re-evaluating this decision.
I do appreciate that there aren’t always alternatives to a piece of very old software, but in this case the decision is between using it and not using it at all. I do also of course appreciate the additional cost and annoyance of having to go through a renewal process every 90 days. That in itself is part of the decision that I mention above, the cost of renewing certificates should be carefully considered and should be factored in. This is something you have to decide on as part of a case by case decision for your own company.
I’d strongly suggest that even if you stick to your existing 1/2 year certificates that you use reminders of some sort to let you know when you need to action things like domain and certificate renewal. It will also serve as a nice way of handing things over to your successor should you ever move on from the company.
I say all this knowing that automation isn’t as easy as it sounds. When I work, we recently automated the deployment of our entire software stack to Amazon. I say entire but the truth is that some parts are still manual. We made the decision that at the time it was more time efficient to keep the manual steps in there, but we are at least moving towards full automation.