Fiesta MK4 - Poly bushes Trailing Arm - pullgees

I fitted poly bushes simply because they were so much easier to fit than the OEM. Now I'm wondering if the suspension will be too ridged that something will break off perhaps the mounting brackets on the subframe. The original bushes are made to be springy.

Have I made a mistake?

Fiesta MK4 - Poly bushes Trailing Arm - foshizzle

I wouldn't worry about it too much, poly bushes have some give in them. You'll know if it snaps off.