I have a Fujitsu 2607 with a LSISAS2008 8i chipset, and after trying pretty much everything I read on internet, only FingerlessGloves’ guide worked! Thank you very very much!!!
As a thanks to the community, I posted online my own toolset and a 2023 updated guide, as well as an updated sas2hax.efi (the original by Marcan was a patched p19 version, here I did the same patch on p20 and I tested it successfully - it may help in some cases maybe). My updated sas2hax.efi is called sas2haxp20.efi.
Everything can be found here:
https://github.com/lrq3000/lsi_sas_hba_crossflash_guide