Not a wood worker. But, I am trying to get out of my normal element (Computers/Video games). I started working from home and my Ikea butcher block I have my computer and other electronics on has the laminate starting to peel off (I have an overly hot and humid room compared to the rest of my apartment) And I'm wanting to go to a full real wood butcher block to avoid those issues in the future. I'm not too worried about how dark the wood is, I have all black legs that I will be using so anything would look good. I just mainly want something that will last 3-5 years or longer if possible.
Finish will be really important then.
I can’t speak to the heat element as I haven’t felt with that as a big factor.
Polyurethane (oil based) is probably the most bulletproof, but it essentially makes the surface plastic and if you concerned about off-gassing/VOCs it’s not great. Water based isn’t as durable, but it’s less toxic. So there is some trade off. It’s a multiple coat process no matter what, with sanding in between. Oil based will likely yellow over time, particularly with sun light so take that into account.
There is a bit of a move to hard wax finishes for furniture these days. There is a greater range of effectiveness in the manufactures in terms of protection, ease of application and VOC levels. The best I know of is Rubio Monocoat. You can order it directly from them. It claims no VOCs. It actually smells good to me (it’s slightly sweet), but that’s not a great reason for selecting a finish. Anyway, it claims to be a one coat application and I have to say that it’s the easiest application I have ever used. It’s almost fool proof so long as you wipe off the excess. Super easy to do. It isn’t cheap, but you need very little, like surprisingly little. You can also easily make quick repairs whereas with poly you have to strip the whole desk down and start over if there is a problem or if it needs maintenance. It’s promoted for furniture and floors, so it has some durability. There are pigment options if you don’t want a pure raw finish. (With poly you would have to stain first, if that’s your thing). That’s what I would recommend for finishes in general. But I have no idea about the heat component. You could probably call them if you are interested.