Scripting is a must

Improvement
It is not quite true that after importing Insomnia one can start immediately. We have some elaborated requests flow which can’t be a match for the request chaining, so no, the suite is not working straight away in Yaak after import, and migration is not possible.
Windows
Yes, there are definitely differences between clients, so importing from any source will never be 100% compatible. I’d love to hear what sort of flows you’re using scripting for.
Our core field of expertise is CIAM, we need full control of the Authentication/Authorization flows as it is one of the things that we test - not only acquiring tokens to call an api. Pre-request scripts are useful, it is needed to prefill the request with such things as the request parameter in a PAR request (OAuth2 flow), or for implementing the JWT profile scheme, to name the least. And as for post request scripting, it offers capabilities for checking response content that can’t be achieved with request chaining.
Thanks for the info! Just to follow up, does creating custom auth plugins also not help with some of the Auth flows?
A custom auth plugin is more for authenticating with the api you want to interact with. It is not that useful when it is the authentication flow you’re testing. And it would not be as flexible as dropping a script. Chaining requests would still cover a part of it, such as propagating a jwt along the flow. However there are some required transformations that chaining requests would not cover.
Got it! I appreciate the clarification