There is at least one sentence (the children eat chocolate before dinner) where it is definitely time-wise and the other occurrences sound more place-wise. So I was guessing it can mean both.
But since I wanted to know and not only guess I looked it up. http://breis.focloir.ie/en/fgb/roimh
The answer is: Yes, definitely both!
(I know it has been 2 years since your post, but, for the benefit of others just now reading it,) in the desktop version, when you click on the lesson, a window pops up that lets you select (click) 'START' to start the lesson, but instead, you can click the 'key in the circle' above 'START' to test out of the lesson, or, click the 'light bulb in the circle' in the upper right of the pop up window to navigate to the 'Tips and notes' section.
Certain grammatical situations call for a consonant to be placed in front of a word, and that consonant’s sound replaces the word’s normal initial sound. That situation is referred to as “eclipsis”. If you’re using a browser for Duolingo, check out the Tips and Notes section for the Eclipsis skill.
But certainly there's value to knowing the language inside and out, how it's put together, how all the parts move. Weird sentences like this help me understand the functioning of the language because it forces me to think, not just go on "autopilot."
"I eat before you eat." = OK.
"I eat before the crab." = Forces me to slow down and think.
Edit: OK, this has been clarified. Leaving the original post in square brackets for transparency's sake.
[Wait. How does this square with what you wrote in another discussion?
"Just like "before" in English, roimh can be used for time or position. [. . .] Ólann Pól fíon roimh an gcat can be interpreted as "Paul drinks wine before the cat does", or "Paul drinks wine in front of the cat". " From: https://forum.duolingo.com/comment/5550345]
Edit: The confusion has been clarified. Original post left below in square brackets for the sake of transparency.
[That is a very helpful clarification, especially since other comments are suggesting that the ambiguity in the English "before" (is it temporal or physical?) is mirrored in the Irish "roimh." Thank you!]