On B&R PLC source code can be also stored, but this option must be manually enabled by owner of the software for transfer. And this is usually not the case, because sw is kind of “knowhow” of machine builder. Not sure how B&R competitors treat with that, but mostly likely they use same approach. But should be not the problem to get in contact of author of your project and discuss with him what options you have. Exchange of hw is one point (very easy using Automation studio), but maybe hw exchange would need project adaption as well and this is something what is machine dependent.