Hi Santiago, this is something I'm looking into but I don't want to overcomplicate the way sequences are currently created.
For now, the best way to achieve this is to create the main sequence with all the steps you want to run, using the no trigger trigger. The way this trigger works is that you can then call the sequence from any other sequence.
Then, create a sequence for each of your variable sequences and then call the main sequence to run the common steps.
This will cover the OR scenario. You can achieve and by having a set of nested conditions and then call your common sequence if all the conditions are met.
Let me know if you have any questions setting this up.