If you hit the nail with the wrong end of hammer, neither nail nor hammer is causing the stress.
If you are having trouble planing the route in Kurviger, there is plenty of users here that are ready and willing to help.
If you have a specific technical problem that other users cannot help you with, the developers are reading as well and will try to solve issue.
Reading rants is not much fun for any of us here.
Kurviger is free of charge for planning so anyone can try if it suits his/hers needs without paying a cent, completely without any time pressure. Full feature set can be tried out for 7 days without having to commit to a subscription.
What I can read from your posts is that you are still not quite used to the user interface.
Undo function is located here:
It works slightly differently than in some other apps (e.g., it disappears rather then gray-out if there is nothing to undo).
There is also Route history function which is can be also used to quickly retrive previously planned routes. Sutrisingly (for me) even when you retrive one of the previous routes from the history it still has it`s own undo history.
Now, I do not know what you mean with MANUAL ROUTING, but many of us here understand using via- and shaping points as manual routing. This may have some special points to observe (like where do you place them and where preferably not), but it is nothing that you cannot learn or what should be causing any stress.
So - ask a concrete question like “how do I route from A to B through C and D?” and you will find help here.