I think the gfp thing will become unnecessary soon so it's probably not worth me adding, but in the meantime you can download the image and use the gpf model separately e.g. here: https://replicate.com/tencentarc/gfpgan
For the "variant seed", I think this is basically "image-to-image"? I.e. choose a starting image and a prompt, and choose the "strength" of the image (i.e. amount of random noise added to it). So basically it's like adding an image prompt alongside the normal text prompt. If that's what you're referring to here, then yep Perchance will have that within the next few weeks hopefully. Currently waiting on a bug to be fixed in 'upstream' code that I'm using.