You can also deposit BNB to Ascendex (formerly Bitmax) straight from BSC (eg Metamask) or from Binance exchange. From Ascendex, you can withdraw USDC to Polygon/Matic Network (MATIC token withdrawals are currently disabled).
The fee is 3 USDC + trading fees for going from BNB -> USDT -> USDC.
Hive to Polygon would look like: Hive -> Binance (sell Hive for BNB) -> Ascendex (sell BNB for USDC) -> Polygon.
I've done this many times without any issues. US residents will need to use a VPN. Ascendex also requires a 24 hour waiting period after enabling 2FA before you're allowed to withdraw.