Use of plugins only once allowed?

I thought I had a simple request, turned out, that the standard license is quite unconventional.
A while ago, I bought Seamless Transitions, a plugin for Premiere to create … transitions.

Now I contacted the author, I could not install it on my new computer, because of licensing restrictions. The old machine is gone, and I thought, it worked there, I’ve purchased it, so obviously I can use the same license on my new PC.

Apparently this is not the case, on closer inspection you will notice that this plugin covers only one-time use with the standard license.

Software/plugins that have to be paid per use?

Use, by you or one client, in a single end product which end users are not charged for. The total price includes the item price and a buyer fee.

Maybe if it’s about templates or WordPress themes or whatever, this can make sense. But a plugin?