Water-based wood sealer
We love the look of birch plywood but since the top surface is so thin, protecting it becomes really important (especially if you're trying to use it in wet areas).
Our carpenter first recommended this floor finish for some maple stairs in our studio, and after seeing how hard and durable the resulting finish was (and also not yellow and not glossy!) we thought we'd try it on plywood. We had already tested a number of different water-based wood sealers on the plywood in our studio (Osmo, etc.) with mixed results, but the Varathane ended up doing exactly what we needed, and so far has held up well even in wet areas.