Advice for CFW update

Hi guys,
in 2021 i jailbroken my ps3 via ps3xploit and updated the OFW 4.87 with the CFW Cobra Ferrox 4.87 (CEX Cobra 8.2).
4 years have passed and I would like to update the CFW.
To upgrade to the CFW Evilnat 4.91.2 [BETA 15], is it enough to download the CFW and update the PS3 via USB stick ?
And which file should be downloaded, PEX or D-PEX ?
Or is it better to update to an older CFW ?

Thanks for your advice.
Tony