how important is consistency in a webcomic, really? theyre very much a 'make it up as you go' work, and readers are aware of that - things switch up in webcomics all the time. i think if the format flipped from page to scrolling back to page, id be confused as to why, but not annoyed unless it was mid-scene or mid-update
and honestly, i think people exaggerate the difference between the two styles. its very easy to find a middle ground that involves slightly fewer, bigger panels, still in page-style compositions - scroll-friendly page formatting.
honestly, so long as you bear in mind that the foremost visual flow of your pages will be up to down due to the scrolling, you can do what you like. especially since this is your learning experiment. if you dont like something, just change it