Little Nav Map is full featured, not complex, and completely free. It’s been used as a valid EFB by other sims, so I’m not sure how this becomes a bad choice if you want to flight plan in a closer real world fashion today.
Beyond that, the sim has a rudimentary flight planner. If you follow Dev Q&A, flight planning revamp is on the roadmap for sometime in 2022, which ideally is delivered by Working Title.
Your dissatisfaction is noted, but the official way to get that customer feedback is to file a Zendesk. Thanks.