Keep the KYC'ed UTXOs separate from the non-KYC'ed (separate wallet or strict coin control). I have some KYC UTXOs that remain "forever" in cold storage and will not move. No need to coinjoin here.

However, every non-KYC UTXO I coinjoin now as the fees will be higher in future. Right now, it is relatively cheap to go into whirlpool as the mining fees are not that high.