I've removed rust stains on linoleum floors with salt and lemon juice. It's worth a try. Also a vinegar soak might work. Keep a towel saturated with vinegar on it and leave it on there wet for a week. Maybe scrub every couple days.
spot tested clr let it soak for a 3 hours then scrubbed. it’s a bit lighter it’s on the bottom so if it discolored not a big deal. I gonna try a longer soak here this week. found clr in a gallon. i’m gonna try the citrus cleaner too.