A suggestion for the configure page of Shipping.ByTotal (http://localhost:xxx...hipping.ByTotal) would be to make it paged.
I migrated our shippingmethod/weight/province/price matrix into the ShippingByTotal table and it now has around 3,500 rows.
The configure list (localhost link above) fails to load most times now, throws an exception with some javascript code, the times it loads the page is virtually not usable as it's taking forever to even scroll down once on the page as it contains all 3,500 entries on a single page.