Off topic but I'd recommend printing this stand on its side vs the back.

In its current orientation the stress would be dispersed directly against the layers and it'll be more prone to break.

If you print it in the side it'll spread the stress across multiple layers. The annoying bit would be the need for supports on that split.

For the lines you could try a fuzzy texture.

I bet on more cooling due to shorter layer time in that area. Maybe the fan is blowing harder, check your cooling fan settings, and minimum layer time.

I would guess it’s a timing issue; since the layers on the front part take longer the back part has longer to cool and shrink in relation to other layers. Maybe a draft is increasing this effect - do you print in an enclosure? If yes, maybe a setting a minimal layer time might help - that way all layers have an equal amount of cooling time.

Layer time, most likely. You can avoid it by setting minimum layer time higher. When the curvy part is being printed, it takes longer for that layer, so it gets to cool down more before the next layer, in contrast to still being a bit hot before the next layer if the layer time is short. This causes unevenness in the looks a bit. You may also decrease the effect by lowering the printing temperature, but I would not recommend it. Also, part cooling fan can have an effect as well.

It looks like it's in line with some features where very little filament is used. This is either a layer time issue, or a retraction issue.

Increase / decrease infill/wall overlap % seems like the best advice I found while googling.

Imo printing on edge would fix it and make the print stronger but that could require changes to the model / printing with supports.

It’s difficult to tell height and things lining up in the photo - if it’s all over the part it might also be feeding issues or ringing. If it’s ringing check how sturdy the platform your printer sits on is or decrease printing speed. What machine are you using with what settings?