I saved some alterations for comparison and now there are too many presets in the drop list how can I delete these redundant presets ?
Unfortunately at the moment this feature is not available on the TonePrint Editor. You cannot delete your presets in the TonePrint editor nor go in a folder to do it. Maybe it will be done in a new version of the TonePrint editor. We might have user recoverable TonePrints with a sharing function MAY BE available at a later point once we will have an infrastructure for a Toneprint community in place.
Despite that, I found a "semi-solution" for you. You can load a TonePrint that you want to erase, change it the way you want for make a new Toneprint and store it on the older one. You even will be able to change the name to something else. It is not directly an erasing of the TonePrint which is not possible currently but a complete transformation of the TonePrints previously stored.