Yesterday I had to factory reset my Xperia and I tried it again from the beginning. I got a bootloop since my mobile was more than 3 hours with the gear animation. My phone was charging and after ~10 minutes I heard the sound that indicates the mobile is charging, so I guess there is something wrong with the startup. Maybe mobile started successfully but the gear animation was still there. After 3 hours I forced a reboot by pressing power + vol up.
---------- Post added at 09:34 AM ---------- Previous post was at 08:39 AM ----------
I want to share with you all my conclusions and inquiries after trying a lot of things. I now have Concept-ify running and all seems to be working. Here are the steps I followed to get it working:
0. First you need to have installed latest sony firmware version on your Xperia M4 (stock MM) and TWCP (recovery.img from the first post, maybe other versions work but I used that). Also, insert a microSD with Concept-ify.zip from first post and kernel SkyMelon 8.zip. After doing some tests I think versions 8.1 and 9 end up failing (or maybe not ). Download from here:
1. Start in recovery mode, and go to WIPE to make a factory reset. This will delete all your data. Do not reboot.
2. Go to INSTALL and select Concept-ify.zip from your microSD. Install it and do not reboot.
3. Go to BACKUP and make a backup of your boot.img partition. Do not reboot.
4. Go to INSTALL and flash skymelon 8 (neither 8.1 nor 9). This will fix WiFi problem. Do not reboot.
5. Go to RESTORE and restore your boot.img backup. Do not reboot.
6. Go to WIPE and wipe dalvik cache. Reboot.
7. If your mobile keeps on gear animation for more than 30 min, force a reboot by pressing power + vol up.
I think the problem is that Concept-ify used skymelon 9, but when they went back to version 8, developers didn't adapt back the rest of components, so WiFi was not working. When installing concept-ify and later skymelon, I ended up with bootloops but restoring boot.img saved my day.
Now I have Concept-ify working with magisk. The only thing I have noticed is Amazon app is not available from Play Store, as it indicates that my device is not supported for that app version.
Best regards.