As long as you haven’t introduced additional frogs into your pond, there is really no such thing as too much spawn. It’s a tough life for a tadpole - they have lots of natural predators and are at risk of various amphibian diseases. Because of this, female frogs lay thousands of eggs each year and only a tiny fraction of them will survive to adulthood. Your pond may contain a big black mass of writhing tadpoles but this is how it is meant to be. Just kick back and enjoy watching these amazing animals.
Moving spawn between ponds, especially wildlife ponds, can be dangerous for wildlife. It helps deadly amphibian disease and invasive non-native pond plants spread. Also ponds that already contain spawn may not be able to support the increased population if more spawn is added. Ponds that don’t have any spawn are unlikely to be suitable for frogs - if they were suitable, the spawn would already be there.