I also have masonite on the walls and it is really stable as long as you use the right type of screw. Otherwise, molly should hold better in masonite than in plaster.
There used to be rubber expanders for plaster that, if I remember correctly, were rated for 20-25 kg each. They were blue and twisted like a knot on the inside. I don't know if they are still being sold.
In the past, there were rubber expanders for plaster that, if I remember correctly, were specified for 20-25 kg each. They were blue and twisted like a knot on the inside. I don't know if they are still sold.
The result was 3 molly bolts as in the picture above. They were very secure.
I still think the anchors should have a wider spacing. I can't believe the engineers haven't figured that out!
The TV is hanging and it's stable.
Afterwards, I think you could use regular plastic plugs and a slightly thicker screw, but molly feels much safer. Each molly can support 50 kg, so with 3, the mollys are rated for 150 kg.
After drilling, I measured the thickness of the masonite and it was 10mm.
If the TV falls, which I currently give zero chance, I will update the thread.
Otherwise, thank you for all the responses, wishing you a continued great summer.