Granted it's been a while since I used a PS4, but the standard media app on there wasn't capable of handling DTS audio tracks when I had one. Which is why I got rid and replaced it with another xbox one. That may be different now, of course, as this was a couple years ago. This issue is somewhat negated with using PLEX though, as that handles the audio for you. But at that time, I preferred to use Serviio for my home streaming.
I dont know the ins and outs of how Google drive works though. Does it allow you to install Plex right there on the remote system? If not, would you not then need your home computer connected to it in order for it to work correctly? (like if it was a mapped drive on your computer, similar to Onedrive). And then your limitation would be your upload bandwidth capability from your home connection, as it would be if Plex was installed on a local machine?
I use Plex in my home, and remote access from my home server, using my home connection. I have Sky Fibre Max, which is apparently around 20Mb upload capacity. And that seems about right. I paid to have the Plex app on one of my ipads to allow me to stream to it from home, as I work out the country a lot. You have some different options with Plex, such as the Plex Pass, which is a subscription service, and gives you a whole lot extra features, or you can unlock a device for media playback only, at a reasonable cost of around £4 IIRC. As I use this function relatively rarely, and don't require the need to specifically download the content to my device, and only need it on one device, I chose the cheaper option of only activating one device, rather than the subscription for any device linked to my account.
But as I am usually on oil rigs, the connection speed there isn't really up to much. Where the likes of Netflix reduces the bitrate suitably so you still get a decent looking picture with lower download speeds, Plex only recently brought in this function. It's difficult for me to tell how well it actually works, as I have no real idea what my connection speeds offshore are like, but when I'm in hotels and the likes, I do still get a pretty decent picture.