I do have this particular one and some others.
And IMHO YOU DO NEED THEM .. and sometimes they
are not enough.
Mainly the problem is when you need to preheat or keep
the heat on large sinking planes MOBOs.
This particular one is good for precision LOW THERMAL profiles
being plastic you may not expose it to pre heaters easily
It all boils down (pun intended) to MOBO size.
I am wondering a metallic magnetic one
https://www.aliexpress.com/item/4000263564047.htmlbut for large sized MOBOs they can not twist with the
bottom heater and holders can not contain plastic.
However magnetics can be fixed to the plate easily..
When things are too odd I use iron bench gigs or
improvised large stands under the heater.
Enough to raise large thermal sink planes
Paul