New construction, do the supports look correct in the attic?
Those look like temporary supports judging from the lack of fasteners, and if so, there's nothing wrong with supporting something temporarily in whatever way works.  I just assume because I don't think most tradesmen would leave an unfastened but somehow necessary 2x4 passing through a living space at an odd angle.  If you look on Youtube there are videos of people doing solo framing erection, using simple ropes, levers, wedges and 2x4 temporary props to hold things in place while they're tacked together.  Sometimes they are forgotten and left in place, but this is unlikely to cause a problem because of the typical limited weight.
If so, they have really nothing to do with the long term reliability or stability of the framing.  Either way, you may need an engineer if you want to speculate on the long term reliability, stability or load bearing capacity of the actual permanent roof members.  Presumably you have already had this done, so you could compare the plan to what was actually built.
If this is intended to be permanent and critical support and has more fasteners than I see, it does look a bit iffy to me, and the solution is the same.  See what the engineering diagrams indicate and if it differs, have the tradesman in question demonstrate his calculations and that he had a right to make them (I'm an electrician, and electricians are given authority to calculate certain things, and with other things absolutely must follow specifications provided by other professionals, so I would imagine framers are trained and have at least some ability to calculate and rework supports.