I wonder if the replay board will run even for 24/7 without having any issues.
That depends on the skills of mikej

In practice if the mechanical stress between the BGA package and the PCB is greater than the solder bonding.. there is trouble. Same if power consumption makes the voltage regulators exceed their power dissipation and thus thermal limit. Dust, moisture or smoke can also mess with the stability. Unusual bit patterns may cause electromagnetic interference within the board, especially if the power capacitors and inductance isn't properly designed. The link between the FPGA and the DRAM may be especially vurnable. Transients or earth loops from external connections is another gotcha.
I hope he does some 24/7 testing to see what fails first.
Some practical things to do:
* Get a power supply with proper AC-line filters
* Measure and remove and ground loops between screen, audio amplifier, power supply, etc
* Fix an enclosure with enough venting holes
* Use ESD protection at ALL times