SLI won't load over port forwarding/out of band on PowerEdge C6420, dracut-initqueue timeouts

I'm trying to boot from the CentOS SLI, 3.0 over iDRAC 9 which I have to use out of band, e.g., port forwarding with ssh, or using a browser launched via ssh -X (or -Y) on a Mac/XQuartz and I've tried Mobaxterm on Win 10. It eventually times out with Warning: dracut-initqueue timeout. While booting there are all these squashfs errors, e.g., Unable to read cache entry and Unable to read page, block, as well as blk_update_request: I/O error. We're on RHEL 7 and 8 (depending on the cluster). I've tried the Linux command line boot options and grub suggestions here. No difference. I have a few cases open with Dell support but they're telling me to just boot locally, which defeats the purpose and isn't always possible. Any work around for this?