Sounds like a bug in Elgg (Ref.).

Is there any way to bypass this?

The only way is to manually make changes to ElggInstaller when checking this step.

Thank you! I changed line 1277 of ElggInstaller.php to "return true;" and this allowed the installer to continue despite the error messages. I don't know whether this will cause more issues farther along, but for now it seems to have worked.

I don't know whether this will cause more issues farther along, but for now it seems to have worked.

The ElggInstaller is only used during the installation process, so this shouldn't cause any issues further down the line.