I'm not familiar with the project that inspired this one, but you should pay attention to hot spots, heat should be equally spread across the whole plate. plus you should have good sensors and provide controllable configuration of heat points for soldering different components according to the manufacturer's datasheet.

I'm yet to venture into the world of expensive but quality solder and flux. I'm still using materials from Aliexpress. When i get into the more quality of boards i will bring in the extra cost of those high quality products. Thanks for your feedback guys!