Notice a commit supporting this version.. would attempt compiling myself but not instructions, and past experience with java aanthing seems like a complete trainwreck to get working.

Hello @XeonG 👋, I am not an official developer of OptiFabric but I know several programming languages.

If you go to the curseforge website there is a download link to the current version.
In the following picture you can see the supported version. There are also older versions available:

You can also see here how it works for me without problems. For this you only need to put this file under .minecraft in the mods folder, to fabricloader:

I hope this helped you and you could install. 🙏

@21r8390 - Thank you for the info. I also got it working with the following:
fabric-api-0.45.0+1.18.jar
optifabric-1.12.10.jar
OptiFine_1.18.1_HD_U_H4.jar

I had to create a new profile using fabric-installer-0.10.2.exe (https://fabricmc.net/use/installer/) for release fabric-loader-0.12.12-1.18.1