I also considered purchasing another board at some point in time. I do like your innovation with the thumb screws! You are probably the first person that has done this and it is a nice solution! Just saw it in your link you posted...thanks!Glad to hear yours fits snuggly. I don’t think it is a manufacturing issue or anything like that. Bamboo like any natural material is going to take whatever shape it wants based on humidity, temperature how the different pieces were glued together etc… It would be very hard to make a wood product hold a consistent dimension considering all the variables.
I thought about buying a replacement cutting board but figured the chance of another one working was about 50/50 so I chose to work out a method to secure the cutting board more firmly. Not a solution for everyone but even today I was out on some very rough roads and not one rattle or knock from the table at all so I’m calling it a win.
Incidentally, the link to the thumbscrew conversation is a just few posts back in this same thread if you wanted see it again.