I read more about mempool during my recent investigation, however I ultimately opted to conduct an experiment using the mainnet mempool. Unfortunately, the node must complete IBD (initial block download) up to the most recent chaintip before it can fill your mempool. But my main concern right now is whether or not my experiment will succeed. If so, how can I obtain some answers? I know it will be very difficult based on my prior experience, but I'm wondering whether there's a method to use the importmempool RPC (remote procedure call), which acts as an interface with a blockchain.
If it's just for experiment sake, use Testnet or Signet instead. I just checked my node and found out testnet blockchain has size ~30.9GB, while Signet blockchain has size ~830MB. If it's still too much, i guess you should write script which connect to someone's else full node and ask for transaction on it's mempool.