For instances of Skandha that you run yourself, Etherspot have added options to protect your UserOps against frontrunners and many other types of MEV.

We’ve done this by integrating the Flashbots Auction API which is a permissionless, transparent, and fair ecosystem for efficient MEV extraction and frontrunning protection which preserves the ideals of Ethereum. Flashbots Auction provides a private communication channel between Ethereum users and validators for efficiently communicating preferred transaction order within a block.

This can be enabled by following the Skandha installation page and changing rpcEndpointSubmit and relayingMode in config.json like so:

{
  "networks": {
    "sepolia": {
      "entryPoints": [
        "0x5FF137D4b0FDCD49DcA30c7CF57E578a026d2789"
      ],
      "relayer": "0x{PRIVATE-KEY}",
      "beneficiary": "0x{BENEFICIARY-ADDRESS}",
      "rpcEndpoint": "wss://ethereum-sepolia-rpc.publicnode.com	",
      "rpcEndpointSubmit": "https://relay-sepolia.flashbots.net",
      "relayingMode": "flashbots"
    }
  }
}

Relayer URLs:

NetworkURL
Mainnethttps://relay.flashbots.net
Sepoliahttps://relay-sepolia.flashbots.net

You can find more information about relayers here: https://docs.flashbots.net/flashbots-auction/quick-start

Or more mainnet relayers here: https://github.com/eth-educators/ethstaker-guides/blob/main/MEV-relay-list.md