Hey,
I have grown Bursera bipinnata in the past, and I have also a little Bursera graveolens seedling grown from seed.
Maybe you want to take a look at my blog for growing info, I treated the Bursera graveolens seeds very similar to the Bursera bipinnata seeds:
https://de-sacris-plantae.blogspot.com/p/growing-copal_2.htmlSorry for my bad english
The Bursera bippinnata seeds germinated very quickly within a few days, for what ever reason the Bursera graveolens took 3 weeks to germinate and just one of five germinated.
I put them on the hottest spot on the heating mat, I suspect that this was maybe too hot...
I attached a pic of the 6 weeks old Bursera graveolens seedling, it seems to grow a bit slow.
Here´s the info I got from Jason Eslamieh from Miniatree Garden on growing Bursera from seed, hope that helps:
Sow Bursera seeds in a well-drained soil medium and cover them with a light top-dressing material, such as quarter-inch screened pumice or coarse sand. Make sure to water the pot well and keep it in an area with high temperature (over 80°F) and high humdity (over 50%). It will take any time from a few days to a few weeks for the seeds to germinate. If the seeds dry out for any lenght of time, the germination process will stop permanently. It is very important to use a potting medium that keeps the seeds moist while draining well.
Once the seeds have germinated, the seedlings will require ample sunlight to remain stout and establish pachycaul forms. If there is not enough sunlight or an intense full spectrum of artificial light, the seedlings will grow tall and thin, which will compromise their mass and density. Avoid feeding seedlings until each plant has developed an ample root system.