When using shellac to fill pores, it takes several coats. But depending on the finish you are using, you may not need the pores completely filled, as long as they are completely sealed. The first two coats of finish should fill them completely.

If you are planning to French polish and want the pores to be filled there is an extra step in the process. Forgive the question, have you done FP before or is this the first time? If it is the first time, are you following any particular tutorial? Typically you would use pumice and alcohol to do the pore filling with the FP process. Or. . . use any of a number of other pore filling techniques before you start FP (it may be too late for some of those with that much shellac on the surface). Of course there is nothing wrong with not filling the pores if that look pleases you.

You can get there with just shellac but it will take longer. Have you flattened shellac on open grained woods before? It sounds like you are describing pores that are not yet filled. If you sand back too hard, you could even expose new pores. Also remember that shellac will shrink a little bit while it is drying. Sometimes you can sand back to level and then see pores when you come back later.

There has been 7 brushed on coats up to this point. I was going to try a shellac french polish, so I am assuming starting with a flat surface would be important
Thanks

No these are not wood pores. They are pin size low spots the in the shellac above the wood.

I think Robbie O'brian has a u-tube on pore filling with shellac.....basically, using 320 grit to develop a dust, then apply shellac, rubbing into pores....do only small areas at a time. I use it and it works.