It's a fine product to use, but not something I would use in early spring nor on freshly overseeded areas for a couple reasons.

For one, you don't want to go too heavy on nitrogen early in the spring to push excessive top growth. Also, you don't want to push said topgrowth on overseeded areas as that will make the existing grass pop and shade out the tender seedlings that are just emerging. That will force you to have to mow which you don't want to do on those seedlings.

Save it for a late spring or fall application and use a more appropriate early spring/overseeding fertilizer.

 

It's a fine product to use, but not something I would use in early spring nor on freshly overseeded areas for a couple reasons.

For one, you don't want to go too heavy on nitrogen early in the spring to push excessive top growth. Also, you don't want to push said topgrowth on overseeded areas as that will make the existing grass pop and shade out the tender seedlings that are just emerging. That will force you to have to mow which you don't want to do on those seedlings.

Save it for a late spring or fall application and use a more appropriate early spring/overseeding fertilizer.

Why does the OP have to go heavy on the nitrogen with this product. If they put it down at 1.5lb/1000 sqft they would get 1/2lb of N per 1000. Would be the same as applying 15-0-2 at 3lbs/1000 sqft. I actually think this is a fairly good choice for a spring application, however, I would wait a few weeks after green-up.

 

That was my idea 2 apps of half rate 30-0-4 and then switch to milo and screaming green 16-2-3 and i have enough 20-0-10 for mid fall and 32-0-10 for winterizer plus i have rgs and air8 ready for next season.

 

This Pennington product has Muriate of Potash (MOP) not Sulfate of Potash (SOP) for the potassium (K) ingredient. Not such a big deal in low quantities for lawns, but something to be aware of if you want to continue using MOP ingredients long term.

https://thelawnforum.com/viewtopic.php?t=4011#p73269

 

One other thing to check is prill size. If it's smaller, it would be usable at lower rates (1/4, 1/2, etc.). If it's too large, coverage will be spotty at low rates. Take a penknife and piece of tape to the store to check.

 

If you can't poke the bag, look for the Size Guide Number (SGN) on the bag. The larger the SGN number, bigger the particle size. As Chris LI mentioned, a smaller SGN product better evenly distributes with decent broadcast spreaders.

https://www.lebanonturf.com/education-center/turf-fertilizer/choosing-the-right-granular-fertilizer

 

Good points about prill size and MOP.

As far as the reply warning about too much N in early Spring: I think the implication was that, being a 30-X-X analysis, it might be easy to put down at a high rate (and therefore possibly also hard to put down at a low rate, in theory). But you don't know until you try it.