There are tricky rim/tyre combinations.
If the bead does not initally seat with a track pump, I do the following:
1. Neat washing-up liquid on the bead
2. Put in a tube, inflate to 50psi and leave overnight
3. Pop off one side of the bead, remove tube, replace valve, chuck in sealant and up she goes…
I reckon it’s definitely worth persisting with it. Without wanting to tempt fate, I’ve had one flat tyre in what must be 5 years of tubelessness.
That’s on a variety of UST/tubless-ready rim/tyre combinations, all inflated with a track pump.