I think a better way to implement this would be to allow pressing Home and End when file explorer is focused, to navigate to the first and last items respectively. This would be consistent with how file explorers (and lists in general) typically work, outside Obsidian.
I’d imagine there could even be an Obsidian-specific spin on this where, pressing these would first take you to the first & last sibling of the focused file, and then to the first & last item in the whole file explorer .