I have used General Finish Stain on my oak dining table. After that I have used 2 coats of General Finish High Performance top coat. Both are water based. Because as careful as possible, I can still see strokes in the application. Can I use a water based spray poly as the last coat for a more even finish?
They are both water-based polyurethanes, so there is no reason why you couldn’t. Just lightly sand the topcoat with fine-grit paper to remove the stroke marks and then spray.
I’m assuming from your message that you used a brush previously? You could also just use a roller to apply another coat of the General Finish High-Performance topcoat, as you’ll get a smoother finish that way – use a short nap or a foam roller sleeve.