Well covers are important for keeping water out of the wells, especially since damage caused by a flooded well is excluded from every policy type I've ever worked with.

I know you're asking about metal, but I've seen some very well done covers made out of stained 2"×2"s. As long the windows aren't too enormous, you can stand on 2"×2"s just fine. Either way, I'd still get the covers like you're planning.