Reverse Mortgage buy back - any experience, advice or help

Hi my elderly parent own(ed) a home in San Carlos. A sibling pushed them into a reverse mortgage a few years ago when they didn't really need it.

Parent still lives in home and is now desperate to buy back his home. He took out 500k at 6% interest in the reverse mortgage, paid back the old outstanding mortgage of 300k and my sibling took the rest (they needed the money, that is why the parent was pushed into it). The reverse mortgage company had appraised my dad's home for $1.5 million at the time. At that time that actually seemed high by about 300k but not sure why they would appraise it at an inflated value.

I am hoping to find someone (disinterested) who could help us determine what is the best course of action. I have read one can buy back the house by paying off the reverse mortgage loan plus fees and accumulated interest owed, so probably way more than 500k now. Since the loan amount was relatively low to the value of them home, I would assume dad could refinance it and just pay a regular mortgage. He should be able to afford a 600k mortgage.

But I would really like a comparison of what is the best course of action as I am sure there are all sorts of pitfalls we haven't thought of.

Anyone else buy back their home and experiences or things to consider? Anyone know of a specialist who we could pay to provide us a comparison of options? Or a website that would help us understand best course of action?