Mining Solo 1 RTX 3070

I have a very basic yet needed question please. I am trying to solo mine Raven on Mole-pool ( as a test ) 2miners had fixed share difficulty..

This port says diff 256. Then when mining I start by a low difficulty in my miner to 2.16G. Then a correction happens and it starts firing shares at a diff of 431.17 M. What does that mean. And if I am sending valid shares at a high rate ( does that mean I will solve a block fast? ) Should I migrate to mid-lvl difficulty? ( Port with 1024 diff?) To get mild work assigned by the pool? I can't make the difference between share vs pool difficulty yet and how are they related or unrelated to solving a block. Please help🙏