I like your post gingerfinger.
But if your kite turns like that, with fully slack rearlines, it is REALLY wonky IMO
Even if your frontlines are not the same length - the kite will not turn/drift at all, with bar pushed out (slack rearlines).
So definitely something wrong if it turns a lot, only on the frontlines.
If it just drifts slowly - well, thats fine.
I am talking about the rear lines though - even if you got all 4 lines matched up perfectly in length - you will more often than not, experience that you need just a tad of difference on the rear line length - in order to fly the kite perfectly straight with tight rearlines
Thats just how it is, and the tolerances are like that - I dont think you can ever change that, in our "low priced" category, without much or any selection