Well I guess we maybe agree to disagree a little…
If the software purports a line to be parallel with an axis… then that is what it should be… near enough is not good enough…
I have the same issue with the rectangle tool, sometimes not creating rectangles… as was discussed in another post… it is just wrong!
and undermines my confidence in the software
If it does not do what it says and users understand, then it should either be removed or or the limitations clearly documented and disseminated… not to be stumbled on by paying users