No problem. Haiku uses hpkg as it's native software distribution format. You can package up a hpkg in the zip and people who purchase McPixel 3 can just copy the McPixel3.hpkg (or whatever) into /boot/system/packages (system wide), /home/config/packages (per-user) to install it. If the user is missing libsdl2 (if you do it shared), then the OS will ask to install it.
If you're statically linking it though, you really shouldn't need libsdl2 in theory as a dependency. Anyway, hpkg or just zipping the artifacts up, either way will work.
Thanks for supporting Haiku!! If you have any technical questions the forum is generally full of help. https://discuss.haiku-os.org