... I could not provoke the block
...is good luck or (the NO block, ... via script) is an FM feature.
You will only get a record lock order if two users (or 1 user in two windows) e open and edit the record at the same instant in time. Commit releases the edit lock so none of these will have the record open and lock for more than a brief instant and thus it will be somewhat random as to whether you get lock errors.
checking for and handling record locks is a crucial part of creating a solution. If you have more than one concurrent user you can not just 'hope' that your Set Field will work. You have to trap for errors and handle them.
If you have to set multiple fields on one record then use the "open record" script step first to see if you can grab ownership of the record. No point in setting fields if you can't, they will fail.
See this other current thread where record locking and 'transactions' is being discussed: Portal Response Time
In the discussion that you attached, I found the answer to my fundamental doubt : I can have several records open to give greater security to the fulfillment of the transaction.thank you very much
Retrieving data ...