Tension is mesh specific. Take 150S. My chart says 18-28. At 28 you are at risk of popping the mesh. Any more and the mesh stages, or doesnt get any tighter, just more fragile as threads are pulled to the max. At 22 you will still have excellent prints, but also have a screen that is less prone to popping. At 28 if you were to degrease and set in the hot Socal sun the frame can expand and increase tension.
If you want 30 newtons stick with T mesh, or go the chart and find a mesh that can accept a 30 newton tension.
For Newmans, especially older beat up newmans, I recommend panels to avoid any dents or nicks on the channel that can rip fine mesh counts.
Newmans can withstand tensions of 30 or more. Statics can get up to 30 with the right beefy frames, but most statics will warp at high tensions unless they have a thick sidewall, most dont.
Al