Odd artifacts - wish there was a slider to dial everything down

I’m new to gigapixel but am a bit disappointed by the lack of controls. I’m using it to upres 10K CG renders (product shots) to 20K.

It seems the most basic settings for Standard and Text & Shapes add a lot of weird textural artifacts.

I’m a bit disappointed my only options are to click each setting and leave everything at 1. To make this work I still need to recomposite the AI version onto the original and pick and choose areas that are decent.

FEATURE REQUEST: This really needs an effect slider to merge the original and the most basic output of a setting.

Take a look at the texture on the black letters, and the odd hard edges on the smaller type. I tried denoising and retrying but the outcome is the same.