I would go for it. Temps are not going to sustain 90s again this year.

I just looked up powerseeders on YouTube. That's a very clever device. The main benefit I see to it is getting an even distribution of seed. Generally that can be done with a regular fertilizer spreader - either a drop spreader or a broadcast spreader. But also generally you have to add sand or corn meal or something to the seed to get the right distribution. Seed is either too big or small to flow right through regular spreaders. But the powerseeder also jiggles the seed down into the turf. Very slick. One thing it really does not do, even though it says it does, is ensure good seed to soil contact. That is done with a roller afterward. Now if they built a roller into the back of the powerseeder, that would be all you need to do the entire job.