As you mentioned I like the SPS:DEC liquidity pool. In that way your SPS can count towards your airdrop as well as your DEC. There can be some volatility in the amount of SPS and DEC you have depending on price fluctuations but overall worth it.

You can delegate your staked SPT to someone like @monster-curator to get curation rewards without doing the work as well.

I don't think SPT in liquidity pool will give you SPS rewards though.