This is a somewhat related question and maybe somebody can help...

I booked a roundtrip J ticket via United to/from Cape Town (not that it matters) and the return is on Swiss. Naturally, I chose to upgrade to Swiss First on the return .

Does anyone know if I were to change my connecting flight to IAD en route to Cape Town...whether it would blow up the reservation? I have a way longer than needed layover and was hopeful either to change it in advance or maybe same day change. But, last thing I want to do is be placed back into Swiss Business accidentally and thus offer a significant donation to Swiss. As noted above, the reservation is out of sync on United.com but is fine on Swiss.com.

Thanks for any help/guidance in advance!