A user called Michail1 tested the procedure with multiple mycelium accounts and says it worked. You have to restore them individually using a popup asking which account you want to restore.
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I have tested with a multiple mycelium account wallet.
It will work for other accounts; however, you have to restore them individually. Meaning, follow the process outlined prior for each account within the wallet seed. You get a popup asking which account you want to restore.

My seed has 6 accounts. 0-5 I restored the first 4 as tests to know that it works.