these guys have given me a means to shoot both a heavier arrow AND still be spined correctly.
Yes, you can shoot a heavy arrow and still be spined correctly. I didn't know that "being spined correctly" was the question being asked though. I was under the impression that it dealt with being over-spined which is somethng different.
Take a look at a 2020 aluminum, at 29" it weighs 392 grains, deflection .426
Then look at a 2512, at 29" weighs 299, deflection .321 (much stiffer, less weight)
What I am saying is that there is not always a direct correlationin increasing shaft weight and increasing spine.
There are also weight tube options to increase weight.You could alsostiffen the spine (if necessary)and go to muchheavier heads if you are looking to increase total arrow weight.