This is second-hand info, but I heard VIAC are refusing to pay out 3a money when you are moving abroad until after you’ve established your residency in a new country.
So you’re in for a nasty surprise in this case with VIAC. For example I know for a fact that US treats pillar 2/3 withdrawals as fully taxable income if you are a US resident. So you would not only NOT save anything on taxes with 3a scheme but overall even LOSE some to US taxes.
Some other providers have no problems paying out just before your departute (=> you have to pay tax to residence canton) or while you’re in tax residency limbo and not registered anywhere (=> you pay tax to 3a institution’s canton). Just make sure to give them enough notice of your intentions.