Here's a link to a newspaper article about a letter from August 1944 that a deserter had written to his family moments before his execution:
https://www.iltalehti.fi/uutiset/a/2016092322359712
It's in Finnish but maybe Google translate will help. The idea is very clear, though. The man states that his nerves just weren't up to the demands and he's certain Christ will forgive him his inability. He also states that the men who will execute him know he is not able to fight anymore but they have to do their duty despite of that. He will die not as a criminal, but as a victim of his own nerves
My grandfather (IR 25, 4th Division) told me about desertions that soldiers didn't want the deserters punished and that they tried to protect their fellow soldiers from any punishment. He said that all understood how difficult it was for every one.
He served in a battalion where everybody was from the same region. They knew each other from before the war and knew that after the war they would be neighbours to each other and to the relatives of those that would die. I'd suspect one would not want anyone executed or put in jail, if the consequence would be that the sister or mother of the executed deserter would live in the same village.