How I did to germinate those seeds...
You should planting the seeds directly in polybag plastic.
Don't put the seeds too deep in the soil,just about 1 cm deep from the surface.
Use 25% shade net if the weather is too hot,or you can put the polybags under the tree.
Give it water every 2 days.
But don't give the soil of Dialium seeds too much water or the seeds gonna rot,but also don't let the soil dry.
For baccaurea,it's okay give it much water.
After about 30-40 cm tall,you can move the seedlings to the ground.
Regards,