What are my chances of being denied entry to Thailand after a previous denial due to visa runs?

You should be in a much better position now since it's been about a year since the denial and 10 months since your last stay, especially if you're coming in clean with a return ticket, accommodation, and proof of funds. Most people in similar situations get in without issues after that amount of time, but immigration has been a bit tighter recently so it's never 100% (at the moment they have been practicing increased discretion) .

If you want extra peace of mind given the long flight, you can use a service to assist with entry, and our team can help review your case and arrange VIP entry to remove the risk:

Get your visa now in the US. Then you know

Just get a visa and you’ll be fine. Probably.

55 days shouldn't be a problem if you have returned ticket. That's just my guess.

Fly to Malaysia, cross by land.

If rejected you are in Malaysia, go to laos, Vietnam, Cambodia, ifvThaulabd doesnt want your money.

I'd recommend a safe entry service if you want to be certain of getting in. Having a visa would also help but still leaves you in the hands of the immigration officer

FAFO