With no scan to look at, I can't give my opinion.
You can't directly post HPT or DHP scans here which kind of sucks, maybe do it as an attachment??
If it's only around 1º of knock total I wouldn't even care. That's not enough to cause any damage or make you worry that it's going to blow up. You could reduce timing by 1 degree and see if it goes away or just leave it.
And 28-30 at cruise is pretty low, you must have sloped it down alot. I ran a hybrid timing table, basically a 2005 GTP table with my 2000 GTP table put together. More overall timing out of boost with closer to stock timing in boost area's. I was running upwards of 35-38 degrees on the freeway and get fuel mileage.
