Would it be possible to add the PTR Patch 2.4.1 on the builds section as soon as possible so players who try out viable builds can categorize them correctly when creating them instead of putting them on the Patch 2.4 section with a PTR tag on it?
You mean, confuse people who play the live game more than they should ever be? It's never been added in the past, can't see a reason for it to be added either really. I mean it's just minor tweaks at the moment.
Right now the 2.4 section has builds from 2.4 and 2.4 PTR. As it is, we may end up seeing the majority of builds being for 2.4 but also some for PTR 2.4 and PTR 2.4.1 as players are mostly flagging them as "PTR".
If one of the dropdown options on the Patch states "PTR 2.4.1", I believe there wouldn't be any confusion when filtering it in comparison to the live 2.4 option.
For what it's worth, icyveins has updated builds for 2.4.1 so there's some guides out there. I greatly prefer the diablofans format so hopefully they get the ball moving soon. Also generally if you filter for the newest builds of a given class here on diablofans, most of the new ones will claim 2.4.1 in the title (and if anyone knows of a magical way to just filter 2.4.1 then please let me know, adding 2.4.1 to the build name field returns a claim of no builds found for me even when I can manually see plenty that match it...) sadly there's using 2.4 items/gems in the links and you need to definitely pay attention to the written part where they suggest the real item to use in case of using one of the 2.4.1 new items.
As you said, there are plenty of new builds in our DFans database - as a matter of fact, basically every build entered recently is 2.4.1, because no one created/edited a build for an old patch.
Also, keep in mind that there are basically no changes to the mechanics between 2.4 and 2.4.1, all that changed are a few numbers here and there and a few details in end-game; but for the most part, and especially the upcoming season start, any build for 2.4 is still helpful for 2.4.1. Except for Solanium-based support builds no build was "broken" or doesn't work anymore.