15 minute wait after grub2 menu before kernel messages appear, Dell PE R420, RAID-5 Fed 27

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I just re-purposed a Dell PowerEdge R420 and put in 3 brand new 15,000 RPM SAS drives and used the internal hardware RAID controller to configure RAID 5. Once in Fedora everything is smooth and fast. However reboots take over 20 minutes. I removed the RHGB and quiet parameters from the cmdline option in grub2. I don't even see the kernel booting messages for at least 15 minutes. It sounds similar to this 2005 BZ. The common kernel problems page mentions the edd=skipmbr or edd=off options, and I've tried the latter, no improvement. Are there any other boot options from the huge list of kernel parameters to try? We are in legacy mode, with secure boot disabled. Once the kernel messages appear the boot time is super quick, perhaps 20 seconds. I also notice that the 3 hard drive green lights appear to alternate, as if the OS is searching for something. Could this be a kernel issue like the one mentioned above from 2005 which was also a Dell, but not a Promise card?

Edit: Check out this modinfo I ran of the RAID controller (interesting that it's a MegaRaid which I learned from one of the linked posts in comments). Should I try finding the hard drive driver to do the same?

modinfo megaraid_sas
filename:       /lib/modules/4.15.9-300.fc27.x86_64/kernel/drivers/scsi/megaraid/megaraid_sas.ko.xz
description:    Avago MegaRAID SAS Driver
author:         megaraidlinux.pdl@avagotech.com
version:        07.703.05.00-rc1
license:        GPL
srcversion:     5121FF8D56A8481586A5CB9
alias:          pci:v00001000d0000001Csv*sd*bc*sc*i*
alias:          pci:v00001000d0000001Bsv*sd*bc*sc*i*
alias:          pci:v00001000d00000017sv*sd*bc*sc*i*
alias:          pci:v00001000d00000016sv*sd*bc*sc*i*
alias:          pci:v00001000d00000015sv*sd*bc*sc*i*
alias:          pci:v00001000d00000014sv*sd*bc*sc*i*
alias:          pci:v00001000d00000053sv*sd*bc*sc*i*
alias:          pci:v00001000d00000052sv*sd*bc*sc*i*
alias:          pci:v00001000d000000CFsv*sd*bc*sc*i*
alias:          pci:v00001000d000000CEsv*sd*bc*sc*i*
alias:          pci:v00001000d0000005Fsv*sd*bc*sc*i*
alias:          pci:v00001000d0000005Dsv*sd*bc*sc*i*
alias:          pci:v00001000d0000002Fsv*sd*bc*sc*i*
alias:          pci:v00001000d0000005Bsv*sd*bc*sc*i*
alias:          pci:v00001028d00000015sv*sd*bc*sc*i*
alias:          pci:v00001000d00000413sv*sd*bc*sc*i*
alias:          pci:v00001000d00000071sv*sd*bc*sc*i*
alias:          pci:v00001000d00000073sv*sd*bc*sc*i*
alias:          pci:v00001000d00000079sv*sd*bc*sc*i*
alias:          pci:v00001000d00000078sv*sd*bc*sc*i*
alias:          pci:v00001000d0000007Csv*sd*bc*sc*i*
alias:          pci:v00001000d00000060sv*sd*bc*sc*i*
alias:          pci:v00001000d00000411sv*sd*bc*sc*i*
depends:        
retpoline:      Y
intree:         Y
name:           megaraid_sas
vermagic:       4.15.9-300.fc27.x86_64 SMP mod_unload 
sig_id:         PKCS#7
signer:         
sig_key:        
sig_hashalgo:   md4
signature:      30:82:02:CF:06:09:2A:86:48:86:F7:0D:01:07:02:A0:82:02:C0:30:
        82:02:BC:02:01:01:31:0D:30:0B:06:09:60:86:48:01:65:03:04:02:
        01:30:0B:06:09:2A:86:48:86:F7:0D:01:07:01:31:82:02:99:30:82 ...