Lenovo usually uses really high quality thermal paste so the temperature difference may be within margin of error. Bob of All Trades on YouTube made a good video about a Lenovo laptop's thermal paste and performance, and I'd assume they probably use the same paste on all their laptops. Do NOT use liquid metal. If you're careful its fine for benchmarking, but please do not use it on a regular every day machine. You'd have to replace it every so often (probably twice a year or so but don't quote me) and thats assuming it doesn't leak out over time an kill your laptop completely. Also, welcome to the forum!