One observation I have about max pain - for any weeks outside of the current week, I find that max pain and put/call walls is nearly valueless. If you look at this week option volume and compare it to next week's option volume, there is nearly nothing happening next week. Don't just look at max pain or the put / call walls - also look at the actual volume associated. A big peak at 600 strike means a lot less when it's 2,000 contracts (later week) vs. 20,000 contracts this week.
That 45k call traded that you mention - that sounds significant. But also realize that monthlies are always busier than weeklies (they've been open longer), and the June monthly even more so - it's been open for two years. And STILL - the big action will happen that week of expiration and not before.
As somebody that has sold both long dated puts and calls (13 months on a put; 25 months on a call), I can tell you why I will move heaven and earth to avoid doing that again. The primary and simple reason is that the underlying resources are tied up for that long period. In the case of puts the underlying cash will be sequestered until you close the position.
In your specific instance even if the shares go up to $800, the change in the option premium won't be as big as you'd like. Even at $800, a March '23 500 put will still retain significant value. You might get to a 2/3rds profit; most likely even 1/2 will need a big move and will be significantly smaller than buying shares or calls would have been.
I DID sell a put with some of that same mindset, but my intent was immediate income in exchange for sequesting some cash. I definitely earned less with that decision than if I'd just have bought shares. "Less" is probably 1/3rd or at best 1/2 (though I still accomplished my objective - so no hindsight / regret for me; only the learning that I don't like positions locked up for so long, unable to make meaningful adjustments).