Well, since you ask so nicely here are my notes and observations after playing with a few offline models:
1. you don't get the info about what kind of checkpoint a diffusion model is so unless you want to keep a database of all released models and checkpoints for offline usage so my suggestion would be NO. though I'd change the 1024x1024 default you use now.
2. since you DO know what model you're online checkpoints are that's a YES for them. Use 512x512/512x768/768x512 as sane defaults for the SD 1.5 models and 1024x1024/1024x1536/1536x1025 for the rest. The bigger the canvas the higher the quality of the image. A lot of SD 1.5 and SDXL base models still use hi-res fix because they generate at lower resolutions.
3. I recommend you also change from using the euler normal to dpm++ 2m beta as the in-chat default for generation. dpmpp 2m is as fast as euler step wise but it produces better results and is guaranteed to be in everything. If you don't want to change the sampler separatly because not all interfaces can do that keep it at normal, but beta tends to work better with pretty much all text2img models out there, unlike say Kerras which literally doesn't work in most non SD based models.
4. I also recommend you use square 1:1 image gen for the character image generation and 2:3/3:2 for in chat generation.
5. I would also like to point out that for on-personal-hardware-generation your default negative prompts do not work. you might have novel AI embeds running for the online checkpoints but they're not there in core ComfyUI. When you generate something HammerAI only sends 'person' for the negative as an example in place of sending the full list of negative prompts, namely 'distorted face, unnatural pose, harsh shadows, poor lighting, over-saturated skin tones, extra digits'. My suggestion would be to go to civitai and have a look in what are the standards positive and negative prompts for each model type you use and replace the negative prompts you're currently using with a series of defaults for each: SD 1.5. SDXL, pony, noobai, Illustrious, Flux, Imagen etc, where once selected, after we put our prompt and if the model supports a negative prompt a negative one, HammerAI automatically sends the usual positives and negatives in the format:
model/checkpoint specific positive BREAK actual prompt we put in or the AI generated for in-chat Argentinean
model/checkpoint specific negative prompts if applicable BREAK anything we ourselves put in the negative column
This WILL improve image quality from what is now by a lot, even if you stick with just 1024x1024 for in-chat generation, image quality will improve for most models. Note. some of the newer models might not need any specific prompts, but older SD1.5 and SDXL base models do. That being said, 128, 256 and 512 tend to be the stable model deviations for image size. 256 preferred over 128, 512 preferred over the other two. preferred in the sense that the models were trained on images limited to resolutions dividable by them and the VAE's trained on sized based on them as well. It doesn't matter what aspect or size the images originally had, diffusion models were trained on a very limited resized/cropped subset of them and the best results can be obtained by using resolutions that are perfectly divisible by one or all of those numbers. I think there's a new Chinese model that can produce images of more random sizes without any degradation, but I also think it's a gigantic models so you know. Note, this is for image generation, image editing has a bit more leeway but you're only doing generation so it matter to you.
ALSO... Mistral NeMo base models are bad at generating prompts from chat... they'er old and most diffusion models have come after them. I'd recommend into looking into some newer small models to see if you can't find something better and summing up chat and creating a prompt for a specific image generator. NeMo base models currently do more of a sum of chat thus far with a lot of caveats like including diologue or complex multiscens in the prompts they create for image generation. And nemo models tend to also be the largest 8GB of VRAM can fully load, not that any bigger model will be that much better if it's a finetune of a really old model or hasn't been trained on how to structure a t2i prompt for certain models. I really don't know what to suggest for this since I don't know what you're telling the model to do when I click the 'image' button in chat but I can see the prompt it makes and send for generation in comfyui. You might be able to improve this by changing how you ask for an image generating prompt to be created.