https://bugzilla.opensuse.org/show_bug.cgi?id=1185174 has been updated. A special test kernel 5.12.0 is available here. Kernel 5.10.16 is available here. Isos for openSUSE Tumbleweed are available here (DE) and here (generic/worldwide). Tumbleweed can be installed in text mode by using textmode=1 as an installer boot option. Once installed, other kernels can be installed. Textmode=1 and other special installation options are explained here.

My i815 motherboard is suffering spontaneous reboots and failure to complete a boot, so no longer available to continue testing. I plan to un-mothball an i810 PC in coming days to try to make this test.