Yes. Lines should touch circles in a smooth way. There could be many arguments why it's kinda important. Like fit to other parts in a final assembly or producti

Yes. Lines should touch circles in a smooth way. There could be many arguments why it's kinda important. Like fit to other parts in a final assembly or production complexity. But even for DIY purposes this minor adjustments would suck a lot of blood in prototype phase, it's a way more simpler to constraint it to be smooth (tangent) and forget about all tweaks needed after dimension changes.