Glad I had presence of mind to test this before forging ahead.
I'm making a couple items that I plan to sign. I don't normally sign my stuff so this has never been an issue before.
The piece of wood shown is Koa scrap. On the right, I sprayed with Deft lacquer last night and allowed to dry. The left was kept bare wood. A couple hours later, I wrote 'test' on the two sides then oversprayed with more lacquer. In less than an hour the 'sandwiched' writing sorta melted and blurred. The one written on bare wood is still sharp and legible.
I used an ordinary Sharpie to do the writing.