The Upscale Generalist works for pretty much all image types. It uses a converted FP8 Version of the JasperAi Upscale Controlnet (for faster infernece) as conditioning combined with SDUltimate upscale. There are two different versions of the workflow. One is a general upscaler and V2 focuses on upscaling facess, bringing for a more realistic skin texture. Jump with key 1,2,3 between each upscaling pass and control the strength via the silder. With key 1 u can bypass the groups. Pass 1 and Two are good for general upscaling, Pass 3 is made for retexturing skin - it uses @denrakeiw new skin LoRa for this process. All settings that I prefixed in this wf work pretty good for me but pls feel free to adjust it to your needs.

You can find all files here

Base Model:  https://civitai.com/models/647237?modelVersionId=724149
CNUP: https://civitai.com/models/1028044/flux-controlnet-upscale-fp8
Skin Lora: https://civitai.com/models/1018511/flux-skin-detailer-realistic-skin-dora
Upscaling Models: https://drive.google.com/drive/folders/11ZmP-Wp96dfcDMUZq0gu1m8kUYOS9tWU?usp=sharing