Roadrunner1390,
I agree that 1/4" is more than 1/16".......but then again it's only 3/16" more.
If you consider that the overall length of the DD wing is about 25", then raising the thrustline by 1/4" only amounts to about a 1% change relative to the chord of the wing. I would consider a 1% change to be fairly insignificant.
Other than possibly requiring a very very slight change in the amount of up elevator trim, I don't think you will notice the 1/4" raised thrustline.
P.S. how fast is yours going ????
I never had a chance to clock my DD before it went to balsa heaven, so I really don't know the answer to your question. I truly wish I did.....but I don't.....and now it's too late.