Seguno understands that page speed is important to shoppers, merchants, and SEO, and the Seguno Popups & Forms app was designed with performance in mind. The short answer to this question is popups and forms affects your shop's page speed as minimally as possible.
Seguno Popups & Forms code loads "async" so that it is non-blocking to the rest of the site loading.
All code is optimized with GZip compression, minification, and globally distributed to give the lowest latencies no matter where you are in the world.