Not too long ago I watched Mr. Mario's HEN upgrade video, and it seems so. To be honest, I don't know much about HEN, nor am I interested in installing it since my PS3s are CFW-compatible. I only installed HEN once on a friend's PS3 Super Slim and didn't experiment with it after the installation.
However, if I manage to get a CECH-3000 (as I plan to buy a One Piece edition in the future on Yahoo Japan Auctions), I will install HEN and experiment with it.
As for CFW, yes, you can install it directly instead of OFW at least from what I've heard. Unfortunately, I had bad luck with that. Based on my experience, directly installing CFW only gave me errors. For context, I installed CFW on my PS3 twice 7-8 years ago by now since the old 800gb HDD I bought used was starting to fail so when I upgraded my HDD again to 1TB. I tried reinstalling REBUG firmware directly, but my PS3 refused to install it. And yes, I made sure to place the update file in PS3 > UPDATE and renamed it to"PS3UPDAT.PUP", but I still had to redo the process. Maybe I'll try installing CFW directly again on a PS3 I bought from Buyee once I have the money to upgrade the HDD.
Since OP did not mention the CECH of his PS3 If OP's PS3 is a CECH-20xx, 21xx, or 25xx (with a Minimum Firmware Version Check required since some 25xx models cannot install CFW), and the firmware is 3.56 or lower, then OP can install Evilnat, which is much better than HEN. However, if OP's console isn't compatible with CFW, HEN will work just fine.
Sources that might be helpful:
https://consolemods.org/wiki/PS3:Getting_Started
https://www.psdevwiki.com/ps3/Datecode