The T12 heating core has had DIY control boards for quite a while. As for the handle, many DIY enthusiasts typically modify a 936 handle. However, the downside of the 936 handle modification is that the tip is quite long, making it less flexible to use. So, how can we solve this? If you're interested, take a look at this article.
You can start by designing your own JBC handle. The JBC handle is more compact, and even after extended use, it remains very flexible because the handle diameter is quite slim, similar to that of a writing pen. See the image below:
Advantages:
The length of the heating core exposure matches the original.
The handle diameter is only 12mm.
It perfectly supports market-standard (Towel Sleep) features.
If your control board has a contact sleep function, then the copper tip area provides excellent contact for that functionality.