Presently it is, at current prices. Realistically, the simplest operational set up would be to sell whatever protocol surplus is needed to finance operating expenses and fund it from that. It will depend on what token holders decide with respect to this proposal. At the moment we are not authorized by the DAO to monetize this surplus to cover operating expenses.
If no surplus is sold, operating expenses would have to be funded out of the treasury runway, which includes ETH. Presently there is enough of a runway for ~1-1.5 years at current burn rates, and may vary depending on actual expenses for things like audits or development times. If ETH is sold or collateralized, it would lengthen the runway somewhat.
Staking 100% of the ETH and selling none of it is a possible and very attractive option also. What these proposals are asking for are clear signals from token holders, who ultimately make the decision.