Tub drain and Overflow Reset advice needed

[Jsmallberries]

I currently have a drop in tub with a 2-inch non adjustable waste and over flow. I'm in the middle of a renovation and the tub is slightly higher due to different sized tile and minor frame adjustments.
What are my options to replace the glued PVC drain?
Once the tub is back in place there is no access, short of removing the tub again. Are adjustable fitting approved for this?

 

[Jsmallberries]

with the the top overflow, I can easily cut and add a coupling to bring up to the correct height.

The main drain, while lower, I can still screw in the new drain,
So even being 3/8" lower, if I can screw in the toe-touch tub drain I should be okay?

..........................................Update, so I need a gasket below, is there any way to add a small adaptor at the top.

I don't have any room to cut this out(see photo) without digging through this sealed trap

 

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[Jsmallberries]

Found a prior post with exactly the same issue answered by Terry

His reply "There isn't a way to lose that 1/2" without building it up new."