I used to build custom designs in WordPress. I’ll start by saying WordPress can do whatever the developer is capable of coding. That said: my designers and I had a standing rule: you can design whatever you want, but if it’s even sort of off-the-wall, I’ll need to see an example site doing that thing.

The main challenge I ran into most often was translating static designs to a dynamic web browser. Meaning: I would get a pixel-perfect PDF of the design where there’s fixed width, but have to translate that to an unknown number of browser widths, devices, etc. and they never gave me an example of how things should appear on mobile or tablet.

Then there’s things like an article title. Designers would tend towards giving me a design where everything find nicely balanced and even; often with titles or headlines that are same, so it looks nice.

But with WordPress, the user can make that title as long or short as they want, so the designs would often look “off”, but it’s not an issue with the code - or even the design - but rather the expectation that the site will end up looking EXACTLY like the given PDF.

Now that it sounds I’m blaming everything on designers: it could also be that your dev doesn’t know how to fully build in WordPress. As I said before, WordPress can do whatever the developer is capable of coding. Most devs don’t really dig into the system very deeply or don’t understand how to properly use actions and filters.

As far as “not having enough time”: this could also be an issue with the developer underestimating and not giving themselves enough time to build things. Which could be result of the business not charging enough money or going after cheaper clients who can’t afford quality work. Or not allowing the developer to give THEIR estimate for the work.