A question about adding brass weights

[Curtiss Cardinal]

I got some PSE Carbon Force Dominator 300s. I wanted them to be front loaded because I like everything I've read, heard and personally experienced witgh front loaded carbons. Well I usually go for somewhere between 300 and 400 grains up front. Well on these I decided to see how heavy I could go I got up to 500 grains and I had as far as I can tell perfect arrow flight and it hits like the proverbial ton of bricks. Well When I made these inserts and weights up they come out over 3" long. So this led me to wonder, Can the insert and added weight be too long at some point? I mean these arrows are flying well and hoting hard and I'm happy but I wonder if it can get to a point where it does something I am unaware of?