RE: never covered.....got a question
The cracks between joined wood pieces is not a significant amount to show through the covering. What you have done already is more than enough to start covering.
What most people such as myself worry about (and what most instruction booklets mean) is such things as large gaps, pin holes, dings, large scratches, mismatched joined wood pieces, dark wood filler and such are what shows through the covering and disfigures the final look.
If you can show pics of the finished product please do.