As a general rule, we shouldn't take seriously any computer models for which the source code is not available.
There is no valid reason why this should not already be a universal practice. If you are looking at any paper which cites the output of a custom-built computer program but omits the source code, it's probably safe to assume that the program is a mess and therefore the conclusions are not (yet) robust.
There is no valid reason why this should not already be a universal practice. If you are looking at any paper which cites the output of a custom-built computer program but omits the source code, it's probably safe to assume that the program is a mess and therefore the conclusions are not (yet) robust.