Currently using Bluestacks 5.2 Nougat32, i wasn't able to install the unsigned .apk despite having all 3 luckypatcher done "Signature Verification status always True", "Disable .apk Signature Verification", and "Disable signature verification in the package manager".
I had to rebuild the unsigned .apk with lucky patcher option of "Re-sign with original signature for android patch" option to make it work again.