does Zinnser dewaxed shellac sealer have any color/tone to it as is..??
If I try 2 coats of amber shellac on an oak floor ...and then 18 months later decide to put on 1 coat of water based poly...can I do that
if I sand a little or is a no go forever for water poly once the wax is present..??

The dewaxed shellac has a little color to it.

You can apply dewaxed shellac on top of waxed shellac, and then apply the poly.

I ordered some dewaxed from Shellac.net It is supposed to be orange We'll see. They seem to be the experts but I dont know.
I am going with 1 coat orange dewaxed and 1 coat water poly. Thats it. I like minimalism.

So, you bought the shellac flakes, right? Meaning, you are going to mix up your own batch.

yes
by the way, I know its better to do a poly coat all at once..but if you had to break it into 2 sessions, is there a good way to
minimise the seam showing between the 2 patches.. 1 would be 200 sf ,the other 400 sf..