No guarantees that any of the following options will work each time, but one of them will work eventually, just keep trying. Have the mod downloaded and ready for install and ensure that the non modded game apk is from an advertisement or a 3rd party site like appbrain.com or applion.jp (no guarantees that you'll get the NSFW but keep trying.) You can also try downloading from the Google Play Store website rather than the app. Once install begins , you can check its progress from the app. That sometimes works as well.
1. Once the install gets to about 60%, install the modded apk at the same time. The modded apk will install faster. Open the game and check for voiceover option.
2. Once the install gets to about 60%, cancel the installation from the play store and quickly install the modded version.
3. Install the Play Store version all the way. Check to see if you have nsfw then uninstall and quickly install modded version.
Good luck and just keep trying.It will work eventually