It’s one of these areas where there are so many different things you can look into that it’s hard to be sure what to go into.
X/Y charting is easier on the A1111/Forge side of things, and can definitely be useful. Bear in mind that different sampling methods need different numbers of steps to get good pictures. Also, some vary more between number of steps, which can be both a good and bad thing.
While, unfortunately, this is easier when you have fast generations, I find it very helpful to just set a fixed seed and change things one at a time and generate to see how they affect things, and just change the seed manually. When you have random seeds on every generation, it can be hard to know whether the change you made or the seed caused the changes in the picture.
A1111/Forge/etc. and ComfyUI store different information in the metadata. With the former, it’s prompt/generation information, and with the latter, it is the entire workflow used as a json (which does include prompt/generation info). In fact, you can actually open a picture generated with ComfyUI as a workflow (which will probably make more sense when using ComfyUI).
As far as dynamic prompting goes, there is an extension for it on A1111/Forge/etc…, and custom nodes on ComfyUI for it, both of which use the same library, so how it’s done will be pretty similar either way. Civitai has a large number of wildcard files you can download for dynamic prompting (as well as ComfyUI workflows).
There’s some information on the A1111 extensions page:
https://github.com/adieyal/sd-dynamic-prompts
It’s best to get an idea of the different types and families of models, and bear in mind they often need to be prompted differently.(pony and illustrious based models are the most likely ones for pony related things. Both are based on xl, but other things are too. And there’s also Flux and 3.5. 2.1/1.5/1.4- are all rather old, and there’s other stuff out there.)
Pony, in general, isn’t great at unified style, and there are a lot of style loras for it, and a lot of models based off of it that do have a better unified style. There are some words that tend to trigger certain styles, though. The Purplesmart.ai discord has a list of styles people have found. You get a feel for words and phrases and how they change things after a while, too. Illustrious is more the sort of model where you can mention artists names and have it change styles, which opens up its own can of worms…
Controlnet and ipadapter are probably good to look into, and img2img and inpainting.
Even if you don’t, glancing through there might give you an idea of things that are possible. (Also, if you install ComfyUI, make sure to also install the ComfyUI Manager, as that lets you easily install custom nodes, and there are a million custom nodes.)