Installed Gridinsoft, it didn't turn off Defender, so I left it on. Plus Hitman Pro (not real time, I don't think) it just runs a scan once a day. No conflicts with Defender and Gridinsoft (which seems to advertise itself as a antivirus and anti malware package). What do you think?
My advice is to uninstall it. It is not an antivirus, it has major issues with false positives and most likely, terrible detection rates. I've got it before as a giveaway and I uninstalled it very soon after uninstalling due to the excessive false positives. You won't have conflicts with an antivirus as it's just an anti-malware software rather than a full antivirus. But personally I would stay well away from this as it's garbage.