Mhhh, instead of adding examples how to make a very complicated process usable, I would prefer to have API support to send large payloads (bodies), without having the user do all the hassle of slicing and reassembling the blocks, similar to (or inspired by) libcoap is allowing. Just my two cents... but maybe in the meantime, having this example would be beneficial.

Some context: in #17544 I want to refactor the nanocoap API and was happy to have found a solution that allowed me not to also to the same changes to GCoap.

Then @kfessel pointed out that this would break gcoap blockwise response. I was confused as I tested all gcoap applications and they worked fine - in particular, gcoap would not do blockwise responses to begin with.

Then @kfessel pointed me to this example that is linked in the documentation. It does not compile anymore with upstream RIOT, but was made to work easily enough.

So the idea is to have this in tree to have something to test against when doing refactoring.

Ok, yeah, then better have a working example than no example at all ^^