While I sympathize with the issue and have experienced similar problems with classical music, I found the listing of composers and the holier-than-thou attitude (because “pop is bad”) grating and soured the rest of the post.
In the Canadian university lingo, co-op refers to a (usually paid) internship that you complete as part of your degree. You usually have a couple co-op terms/semesters along with your traditional terms. For example, you may start your degree with two semesters of classes, then a semester of co-op, then one of classes, then another two co-ops, more classes, etc. until you complete the degree requirements. Degrees with a co-op requirement usually will make mention of it (e.g. Software Engineering with co-op).
If not using something like bind, but willing to run a dedicated dns server for acme challenges, acmedns offers something similar.
When you generate a new account, it gets given a unique subdomain. You then cname the challenge domain to the acmedns subdomain and the account can only affect the associated subdomain.
I’ve seen them in stores in Canada, but they’re usually more expensive than the 454g blocks. Expensive enough that it’s usually better to buy the block and portion it as needed.