Hi,
I'm dealing with ReactJS sites on a daily basis and luckily haven't seen any big issues. But the most common issues I see that come across are that Google isn't able to view the content on the page. What is usually the starting point is using the Google Fetch and Render tool in Google Search Console and from there figure out if the page is being rendered correctly. If not, next steps are likely going to mean that you need to fix that first before moving on to other areas.
Martijn.