The stock firmware from Anathema post is probably the most updated firmware with unlocked feature. Because gibus’s Hipad Pro that has been claimed is now unlocked. You can check from his post here.
Usually Android drivers that allow connection between PC and Android devices are provided by Google Andoird official website. But there are specific drivers for such types of Android devices as Qualcomm (QSD), Mediatek (MTK) and Unisoc (SPD) that require their own drivers for allowing specific access and functions. For example, entering Download mode in Qualcomm, Mediatek or Unisoc devices will require their own drivers and Flash tools to flash firmwares in Download mode. The device manufacturers like Chuwi don’t create drivers for specific devices since there is no need to do that. To unlock bootloader for specific devices will require the official unlock tools and specific methods. For example, Xiaomi Android devices require Mi Unlock tool with specific method to unlock bootloader. Or Samsung devices require Odin for flashing firmwares and unlocking bootloader.
In some specific Android manufacturer like Huawei, they don’t allow unlock bootloader since 2018 and they don’t provide official unlock tool or method anymore. So there is no possible way to unlock Huawei devices since then. I had Huawei P30 Pro in 2019. In case of Realme, there are some models of their each device that are not able to unlock. For example, Realme X50 5G allows only RMX2051 model that deeptest app (unlock tool) can unlock. There are about 5 other models of X50 5G that cannot be unlocked by deeptest app or by any means. I had Realme X50 5G RMX2025 and RMX2075 models in 2020.
Nowadays Samsung devices require no unlock tool to unlock bootloader. Just activate Deverloper mode and allow OEM unlocking. Reboot the devices and done. I have been using Android devices since Samsung Galaxy S1 with Android 2 Gingerbread over 10 years ago. Qualcomm devices are the best and standard with many great features. Mediatek and Unisoc devices are new with less features but still powerful. For example, Mediatek and Unisoc do not have L1 Widevine available or no Widevine. This cause Mediatek and Unisoc devices unable to play FHD or 4K or 8K movies by major streaming platforms like Netflix, Disney+, HBO Max and etc. Hope Chuwi will release more Qualcomm devices later on.