I have confirmed that YES, it is possible to donate directly to Purism without using Coinbase. However, I do not know the wallet address. Pinging @goran-stevanovic to provide it.
…and FYI for those who don’t mind using Coinbase:
Donating with cryptocurrencies using Coinbase
Navigate to the donations page in the storefront. You can make donations in (USD$5 for me) increments. Add however much you want to your cart, then go to checkout. Underneath shipping/payment/account information fields that will need to be filled out, you’ll find payment option radio buttons; click the “Cryptocurrency” radio button, accept the terms, and select “Proceed to Coinbase” to complete the transaction.