I've not been there, but doesn't Gröna Lund have their Intamin drop tower straddling a pathway? Presumably it costs more compared to having the platform on the ground, and then there'd be issues around getting people to the ride. It feels like one of those things that could be a cool project, although 200ft wouldn't be exceptional by modern drop ride standards, so perhaps it wouldn't be worth the cost. Particularly if the throughput was quite low. Because of all the logistics around it, it wouldn't necessarily be a cheap project, but if they got rid of Ice Blast it would free up a chunk of space for a new project. I've not been on Ikaros, but it looks like a cool ride.