First things, they're not anachronisms if they're with aliens but I take your point ;) and would respond by saying that these episodes were just an especially egregious example. I can deal with it up to a kind of period-neutral, base-level point, but it just tipped way over that for me.

Sure, as a whole I like Goes Forth better, but I think III has the best Blackadder

Would like some input:
My only real nails-on-a-blackboard complaint from this episode was the reliance on anachronisms in the script and direction. I reeeeeeally like the dynamic and the discussion between the Dr and Isildr, but the tone has been almost unbearably 'modern' for a period setting- From the Dr sure, that…

Bubblegum tastes like Science (c), which is the primary ingredient in all fluorescent food/beverages. That acrid sensation of your tongue being paintstripped by fizzy straws? Science.

Fernandes - Ever wanted to taste colours? Synesthesia meets soda

'Speakeasy' with Paul F Thompkins hosting is a 1-on-1 interview series on youtubes which I'd say is on par, and with this kind of tone :)