I've recently been searching for a simple, easy yet cheap way to reflow SMDs on a PCB board as I have never tried it before and always wanted to create a small and compact circuit. I then found a crowd funding campaign (whom I will not currently name because my point isn't to advertise) of a product where instead of a soldering oven, it was a hot plate. However in general, hot plates aren't the best for reflowing as the heating is uneven unlike this one where it claims to have an even heating surface (also because it's quite small).
If such product exists being a hot plate that evenly heats up the PCB, how would that be anyway advantageous over a soldering oven? One way I can think of is being able to re-shift the components if they move during the reflow. Any problems or disadvantages?
In addition, Is it safe to put components at 219 degrees Celsius when their max storage temperature is 150 degrees celsius? Looking at the reflow process, for 75 seconds, the oven or the PCB reach over the max (and the hot plate crowd funding product follows this exact same profile). And when looking for a PCB, what aspects should I be looking for to ensure it is reflow friendly? I'm guessing most PCBs are designed for this.