I don’t think it’s a minor delay. In other places where gauge changes are necessary, I think it typically takes on the order of an hour or a few hours, so if you need a big logistics operation across the border from Sweden into Finland, that bottleneck is going to absolutely murder your throughput.
The land border between Sweden and Finland is in the far north where few people live. It would be preferred to not do switches there because that means you need to build/maintain a town for all the needed workers (and families), and said town won't provide much opportunities for any other jobs. In short if you must switch gauges you really want to to be in a smaller city (maybe 100k people) that has other reason to exist so you have a pool of people to hire, who have other reasons to live there and thus have family there.
I hadn't considered throughput but that's a good point. Under normal circumstances even a few hours is meaningless but if you need to get lots of trains across the border in a short span of time it starts to accumulate.
