Been there, done that. I published my doctoral research code [1] so that others could inspect, verify, replicate, extend, etc. YMMV, but the feedback I received from other researchers ranged from neutral to surprisingly positive (e.g. people using it in ways that pleasantly surprised me). But let me expand on my own experiences while developing that software, trying to figure out how to replicate the then-current state of the art.

At the time there were two widely used software packages for phylogenetic inference, PAUP* [2] and MrBayes [3]. The source code for MrBayes was available, and although at the time I had some pretty strong criticisms of the code structure, it was immensely valuable to my research, and I remain very grateful to its author for sharing the code. In contrast the PAUP* source was not available, and I struggled immensely to replicate some of its algorithms. As a case in point, I needed to compute the natural log of the gamma function with similar precision, but there was no documentation for how PAUP* did this. I eventually discovered that the PAUP* author had shared some of the low-level code with another project. Based on comments in that code I pulled the original references from the 60s literature and solved these problems that had plagued me for months in a matter of days. Now, from what I could see in that shared PAUP* code, I suspect that the PAUP* code is of very high quality. But the author significantly reduced his scientific impact by keeping the source to himself.

[1]: https://github.com/canonware/crux

[2]: https://paup.phylosolutions.com/

[3]: http://nbisweden.github.io/MrBayes/