When tracing in Illustrator, I'll use the white arrow to make sure I don't break the link between the handles and keep fluid curves but is there a way to also make sure both handles remain the same length as I tweak them (ETA: meaning, after I dragged out the initial point handles)?
This is a much needed feature.
As far as I'm aware, only 3rd party plug ins offer this. Better Handles was the best at this, but they are now gone. Bought out by Astute Graphics.... which has seemingly integrated the code into their PathScribe plug in. Which I believe is now part of their VectorScribe package (They have it, but I'm unsure which package PathScribe is actually part of now. It may be part of InkScribe.).
With PathScribe you can merely shift-click a handle to equalize the lengths, changing only the side of the path being equalized.
There may be a way to equalize while dragging. If there is, I'm unaware of it. I've never worried about it while dragging. I always reset to the smooth point and drag both handles when that's needed.
Other than that I think this is essentially a duplicate question: How to adjust two handles equally? -- Nothing has really changed since that 2014 question.
VectorScribe 3 (new) seems to have more functionality for this: https://astutegraphics.com/software/vectorscribe/
Instead of using the Direct Select tool (white arrow), try using the Anchor Point tool (looks like a caret character). Clicking and dragging on an anchor will redraw it with equal length handles, and you can change the angle and length of the handles at the same time.