bitcoind – Find out how to mine empty blocks?

If I researched it appropriately, as a pool operator, the methods for mining empty blocks

• Take heed to stratum jobs of different swimming pools and begin mining on prime of it earlier than you hear it “on chain”.
• Listening to hashblock zmq message and creating empty block template to be despatched to miners.
• Listening to bitcoind up to date block tip message and creating empty block template to be despatched to miners

A couple of questions across the similar:

1. What are the professionals and cons of every technique? Can somebody level me at an evaluation if it exists?
2. In what scenario(s) would getblocktemplate name offer you empty block? (with transactions area as empty)
3. How do the highest swimming pools (by hashrate) mine empty blocks? What methods do they go along with it normally?
4. Does zmq hashblock obtain and validate the block first earlier than sending notification or does it notify as quickly because it hears a couple of new block?
5. Whenever you hear zmq hashblock after which instantly name getblocktemplate does it at all times provide the template for the brand new top or is there additionally a chance of it providing you with a template for the outdated top?