I read your license agreement, but failed to understand this:
Example: I purchase a monthly subscription, and download e.g. 20 icons. I don’t need more than these. I, therefore, terminate the subscription in the following month.
Am I allowed to use the 20 downloaded icons without linking forever?
Yes, absolutely! You are allowed to use all the downloaded icons without linking forever. We even have an article about it in our FAQ.
By the way, our FAQ has some other great articles explaining things about our website. You may use it instead of reading that boring License Agreement. If you have any other questions, let me know, and I’ll be glad to help!