Yes, if your travel pattern is as you described, you should be able to enter again on a normal 60 days visa exemption without needing a visa in advance. When you arrive, you will be stamped in for 60 days, and you can later apply for a 30 days extension at immigration if you wish. As always, the final decision rests with the IO you stand in front of, but with an eight month gap from your last entry snd no border bounce and no extensive entry history, this is normally straightforward.
It is a different question if you have an extensive entry history. The question here was simply whether the borders were open or not. All borders with Cambodia are of course closed now, as they have been for months, and at the Lao borders there has been chaos for a long time, with people not even being allowed to leave Thailand unless they have a visa that allows them to re-enter.
Good, you can apply no earlier than 90 days before you travel, and it is generally recommended to submit the application approximately 4 to 6 weeks before your departure.
Processing times vary between the individual embassies and consulates, so you should check the website of the one responsible for your jurisdiction. You should expect some delay now as we approach the peak season.