Powder coating currently does have different finishes including wrinkle and hammer tone at no addition charge other than gloss.
I interviewed 4 shops that did powdercoating. Some were automotive, hot rod and resto shops, some motorcycle, one telescope (!) business.
They all told me that the smooth, glossy coating was "it" with PC. :shrug:
++++++++++++
So, for your perusal, is the shiny PC job I accepted. I don't think it looks so bad. Yeah, the flash makes it look more orange than natural light...
PS, Wouldn't the outside of a chargecooler be about the same temp as an engine?
++++++++++++
Part of what you pay for with PC jobs is the prep. A good shop will mask off any threaded holes or the bolts won't fit. Bare aluminum areas must be masked as well, unless you want to buff the powder off yourself (I did that on the naked aluminum ribs).