I know how complex it is, and i know how much ressources it consumes, but why other API providers do it without restriction ?
Block.io is a simple API who does the job, now for security considerations i didn't went too much in testing as i never had to use it in a production environment, i just know that it is accessible, easy to use, clear UI. And these are very appreciated qualities.
Other API providers restrict usage of their APIs, and do not offer it for free.
Block.io does not do any job, and their API is shit and not free, I used them for a year and it was a pain in the ass to work with them, they use STRIPE to bill their customers even when they pay with bitcoin, what the heck ?
I used them in development only, i won't pay for an api, especially when i don't need to use it, it is just that APIs are easy to use, and provides quick deployment.
It can be a pain for sure, especially if you need methods they can't provide.
Have you switched to annother API ?