When using Google webmaster tools I always get a blank page when rendering. However, the site is getting indexed as unique content to our site is easily searchable.
Should I ignore Google’s rendering issues?
As a side note I have noticed that the cached versions of our pages is just the pre-js splash screen.
if your site is rendered by javascript, specially with any one, which runs after load, so the fetch as Google in the search console will probably show nothing, and you can ignore it. Because fetch as Google delivers a page's snapshot at a certain moment of page's rendering, at which your javascript doesn't load any content.
All your content loaded by javascript should be visible in the Google cache - at that place Google shows the page in the state, when all (most) javascript already fired. But if there were any long timeout, as well in cache the page's content could be missed.
noscript tag) is generated strictly after the window.load event is fired. ala window.load=function() {setTimeout(downloadPage,0);};
– user3338098
Jan 25 '16 at 18:48
Should I ignore Google’s rendering issues?
I'd take them seriously as much as I can.
What your question tells me is that some bots are capable of rendering javascript and some are not.
... However, the site is getting indexed as unique content to our site is easily searchable.
Then the bot that indexes pages must have the ability to understand Javascript.
I have noticed that the cached versions of our pages is just the pre-js splash screen.
I'm guessing your website is Javascript heavy. You're in luck for having the pages indexed. You need to have text on the page that does not rely on Javascript then all Google bots will process the page much better.
Also, on http://www.webpagesthatsuck.com/does-my-web-site-suck/does-my-web-site-suck-checklist-part-one.html the author mentions in the checklists for bad website design:
Our site breaks when visited with the Javascript turned off. (People turn Javascript off for security reasons.)
I'd suggest going over the entire checklist, making sure your site doesn't score any check marks in that list then test it again with the google bots.
