GMO's with long term testing including multifactor interrelationships with the environment prior to release for ingestion by humans.
So far that has not been done.
I am avoiding roundup ready crops for the foreseeable future.

I'm glad to see many approaches being tried and tested.

Insects, bacteria ..
Some species are beneficial to us, some are not.
That is why ultra-sound and fungicides have side effects.
Making the chosen crop resistant is likely to be more effective. That is the object of genetic engineering.