As a home inspector one sees various types of home made repairs such as this. I would think that replacing the 90 and making a proper repair would be almost as easy and definitely without worries of future issues.

As you can see the repair appears not to work due to the stains below it. A simple repair such as this can help reduce red flags for home inspection reports!

The other photo shows a leak that is active and that home owner didn’t have heat tape! I was able to simply tighten the nut and “no more leak”!