Spring currently supports:
Adding a Multi-sig wallet address as the fundraising wallet.
Spring currently does not support:
Logging in using a multi-sig wallet.
Contributing through a multi-sig wallet.
Since it is possible to add an investor to the allocation management manually, an investor can still contribute directly to your contribution wallet using a multi-sig wallet. You can add the TX hash to the allocation management momentarily after the investor has contributed.
We plan to expand our multi-sig support in the future.