Moving the attachment point back might make it pull harder. Slap some self stick harbor freight wheel weights on the outside along bottom edge, will surely pull better. At least half of the board should be under water. I have a homemade wood set that pull okay. Got the amish outfitters, pull better.

Releases:
I use chrome shower curtain rings with white plastic heavy duty clothes pins for releases, then size 10 rubberbands. (1InTheHome Multi-Purpose Hanger Clips (24 Count) on amazon)
If the bite is lite or lots of shorts (july) the rubberband gets bit in a straight line in the jaws of the clothespin so it can slide out with some resistance.
If the bite is hard and all big girls(spring) I have the rubberband loop behind the teeth of the clothespin so it must break to release.

I have also been with guys that break the rubberband and pinch in a store bought release.

They don't always release, but can deffinatly see the rod tip indicate a fish. The furthest rod will have an odd jump when the line hits the water and pulls out. Fish jiggle. Point rod at clip, real up some slack and give a huge hook set to release them.

Get 100 releases. Sucks to pull boards in because you ran out