I primarily use my itch account for sharing my jam games, but also have a paid game available. Currently I'm finishing up a bigger commercial project and  am wondering if I should make a more 'professional' studio account to sell it from, one where the profile isn't filled with jam games and prototypes that might reflect poorly on the game; because 'your average customer' might not appreciate the difference between jams and my more long-term work. Anyone have any thoughts on this? Do you sell games from an account where you host your gamejam entries? Am I overthinking this?

Based on my analytics, most people do not browse the rest of my offerings. They look at the single project that they found in search. 

I assume this because they'll find one of my graphics packs using the term "gothic" and only view that one package. I have three "gothic-themed" graphics UI packages.  If they had clicked on my profile, they would most likely have viewed all three.

I had thought of creating a different page for my graphics and games - but instead I've just changed the names. My graphics start with "Graphic pack" and I sorted them to be right at the bottom of my page below my games. You could do something similar with your jam entries. 

Having several completed game on your profile might give someone more confidence to buy one of your games, as they can see you have some experience and the game will most likely work.

As a gamer I can tell you, I regularly check out profiles from the game dev I would play a game. But I cannot tell you, if it is benefitial to separate stuff. But I am inclined to think so.

Scenario: You make your professional game and get followers. Those followers now get flooded with your jam things, completely different in style...

You could look at some youtubers for reference. Some of them have multiple accounts for thematically different videos. Like, you would not necessarily want to see let's play videos from your favorite fashion influencer.

It is a different question, if you would only have like 3 games. You have about 50.

Of course you can always tidy up your profile and sort games in collections or something like that. But if you make an actual commercial game and have started a small company, you might want to name the account accordingly. It might look fishy, if the shiny new game of Foxy Voxy Gaming get's released on an account named voxel.

I would hide the jam games, and put them all into a collection that is visible at the bottom of your page titled "game-jam games".