Yes, MEGA still forces 3-6 hours (depending on what you use, I believe) of downtime after every 5 GB for non-premium users. For a three hour wait for the UHD version that’s roughly 30 hours of downtime. MegaDownloader supposedly bypasses this, but I haven’t been able to get it to work.
VPN or Proxies with Jdownloader2 or MegaDownloader
Yeah. They don’t seem to be putting up too much of a fight against VPNs. You can use their official app, logged in with your non-premium account, and switch your IP every 5 GB, and it will resume download.