If the "expected score" is accurate at this size, you should not search further. You may well find a poly that's 5% faster by completing the search, but it's pretty clear that 5% of sieve time is greater than the polysearch time.
However, the Expected Score code is simply guesswork without previous experience about its accuracy, you don't know if you might improve by 10% or more. I'd compromise, and search a couple more hours if nothing comes close in that time, I'd assume I got lucky at the outset and proceed to sieving.
A5 coefficients below 10000 should not be searched msieve takes longer at very low A5 values to do the same work. Also note skew is 50M, very high for this size of number; this occasionally causes hiccups in later stages (I have not run into such a hiccup yet, but I follow Frmky's advice to use large A5, say 550M for this size number). Large A5 coefficients have lower skews than very small values.
