Tolino Vision Color Bootloop

[015226066237]

Hello, I am at the end of my wits. I converted my Tolino Vision Color into Kobo mode according to the instructions in notmarek's github repo:
https://github.com/notmarek/KoboTolinoFindings
I installed the update.tar to activate devmode, then switched to Kobo mode in the developer settings. Then I used the downgrade firmware from the same page to downgrade to version 4.x, in order to be able to install Nickelmenu, KOReader etc.
So far everything worked fine.
Then I found this page:
https://pgaskin.net/KoboStuff/kobofirmware.html
From there I downloaded the latest 4.x firmware for Libra Color (v4.45.23697) and installed it. After installing, my Tolino is now in reboot loop. It starts, is responsive for ~1 second, then freezes and reboots after a minute or so. If I am fast enough to click the Connect button I can connect via USB. but all FWs I put into the .kobo directory did not do anything. Does anybody have a proper recovery firmware that can help me here or any other hint?
I also tried upper (and lower also) page button plus power button to get into recovery mode but that doesn't work either.
I hope I didn´t cripple the device too badly...

[Waldy]

Hi,
first, connect the Tolino to the charger for a few hours.
Then, disconnect it from the charger and try to turn the device off completely by pressing and holding the power button (this may take 5 to 40 seconds...). I realize this might be difficult in your situation, so try performing the action a few times. Once the device has turned off completely, press and hold both a page-turn button and the power button simultaneously for 5–7 seconds. Release both buttons when the indicator light goes out.
Once the restoration process is complete, the device will most likely be running firmware version 5.15.x. The Tolino will remain in Kobo mode, as you had previously switched it to that mode. Now, to revert the Tolino Vision Color to version 4.x, install this firmware: downgradeVisionColor the recovery partition will be overwritten.
The instructions in notmarek's GitHub repo worked perfectly with older firmware versions.
Starting with firmware 5.15.x (or perhaps earlier—I don't recall exactly), an issue arose regarding updates after switching to version 4.x, just as you described.

5.x to 4.x for other devices (first switch the Tolino to Kobo mode using Devmode)
for Shine Color: downgradeShineColor
for Shine5 BW: downgradeShine5BW