Feature Request: Allow custom models to be set as the default upscale model.

[alkamine]

While the application does allow custom models to be used to upscale images by inputting the directory into the configuration dialog, it does not allow the custom models to be set as the default upscale model. It would be very useful if this was implemented so that people don't have to manually scroll all the bottom of a long model list and select the custom model at every upscale.

[tumuyan]

In the current version, the “model” that you see in the UI is not just a model path; it also includes other automatically generated parameters. If users are allowed to set a custom model as the default model, many issues will arise.
As an solution, you can use the preset command for custom model , just like ./realsr-ncnn -i input.png -o output.png -m /sdcard/reassr/models-ESRTAN-WTP-ColorDS