I think 4 days for germination is optimistic. I don't know what kind of set up you have, but even with the baggy method, it took 1-2 weeks for the earliest Washingtonias and Phoenix to pop, and those are very fast. I started mine Thanksgiving weekend.

I tried sowing one of each seed (S.palmetto, Butia, Trachy, Ph. canariensis, Sago and W. filifera) in containers, and used the baggy method for the rest. The washies and phoenix popped fast (they are 2-3" in 2 months now), the 1st sabal is starting to pop and the rest have done nothing so far using the baggy method. The container grown seeds have done nothing. The only heat I used was the top of the water heater. 70-74F.

This is my first go-round germinating palms seeds, with the exception of date palms. I'm working with what I have in my basement as inexpensively as possible, so I don't have the optimum setup. This is a learning experience for me. It's interesting to see what others successes will be.

topher, sounds like your doing right buddy.
I found that it really does not matter on depth to germinate, just AFTER they pop, the depth that you put the radicle has been my hardest thing. But depth to get the seed to pop shouldn't matter.
The ONLY way it might matter on depth when popping from what I have found is this...
When I put seeds in a 3" deep container, on heat, the seeds pop A LOT LOT LOT faster than when I put the seeds in a 6" deep container on the same heat. But as far as depth of the seed from the top, not sure it matters. I simply throw the seed in and cover with just enough to cover the seed, maybe a quarter ince.