An interesting discussion. There are a range of “aids” that can be used starting with a hard copy of TCD. Surely that is OK. The on line TCD has some basic word finding facilities and there are lots of specialist on line tools. Then there is this forum. At one time an ex member of this forum posted completed puzzles on Facebook early in the week. Not sure if he/she still does.
Which if any of these you use to complete the puzzle for your own entertainment is a matter of personal choice.
Which you use if you submit for a prize is a matter of conscience. My feeling is to stick with TCD if submitting.