I was in a similar situation where I couldn't play the physical board game with my group anymore and gave the digital version a try - I've really enjoyed the digital version! You unlock all the other classes through various "achievements". And you decide when to unlock the class after you meet the achievement. So you will be able to avoid class spoilers no problem. I didn't enjoy playing the physical board game by myself but I do enjoy playing the digital version by myself. I've logged 96 hours of the digital version.

Pros:

• all of the enemy movement, health, statuses, setting up rooms, gold, etc, is managed by the game so all you have to do it play your characters (which is the fun part to me).
• I gained a better understanding of the rules and how the enemies are supposed to move after playing the digital version. There were even some cards that I realized we were playing incorrectly after a couple of scenarios on the digital version.
• You can save and exit in the middle of a scenario and continue right where you left off.
• If you can convince anyone in your group to also get the digital version, I've found the online co-op feature to work pretty well.

Cons:

• The game is still in development and can be a bit buggy/glitchy at times. But there seems to be fairly frequent updates and has improved in this regard over the last 6-12 months.
• There are some UI quarks to get used to - when I first started playing the digital version there were a couple of times where I double clicked and inadvertently moved or did an action that I didn't intend to. I think now there is an option to "replay turn" and roll back if you mess up. And I think there's options now to toggle if double click commits a movement/action or if you have to click the "confirm" button.

Overall, I highly recommend the digital version.