We have done nothing but go for managers who have the so called 'PL experience' thing and it's been largely an unmitigated disaster. You should bring the best person in whos profile fits the job criteria regardless of which league they're from. Also in theory we run the DoF model at Everton so really we should be looking for a more 'head coach' type who is only interested in player development and preparing the team for each match rather than an old school manager who wants a say on everything.
One of the reason, why we are where we are. The club hasn't had a proper strategy in 10+ years and was poorly run. In the majority of time we kept spending beyond our means. The consequences are visible now. There is some much going wrong or went wrong. This got to change, but it's a tenacious and long process to go back to the old days. For me, it doesn't have to be a prem proven manager, but someone that is ready to work in a club like Everton and worked on a good level before like Iraola and implemented good principles there. I wouldn't even hesitate, if someone like Glasner or Iraola were interested or available to join the club.
Dyche is a short term solution till max 2025, you know what you get, but also what's missing, We talked about these points a lot. The next one needs to be someone with a long time vision, as you said. I also agree that the priority of the manager should be on the daily work on the pitch to get out the max of the players having a good defensive and offensive plan , and not to have a full control like Sir Alex, but yet to be involved.
The question is what is your expectation right now for the next 1,5 years, what do you think is realistic, what is your main priority? Till BMD for me it's to keep this club up and build a solid foundation get healthier financially, then to bring in a suitable manager, that can build up on that step by step in a long time vision, make suitable transfers for that etc.