Sounds like a major fault in having an automated Zargon is no accounting for homebrew calls to smooth over the rough edges.
See
the Rescue of Sir Ragnar, the Anti-Climax for similar issues.
Kids may be happy to roll to the door perfectly safe but adults get annoyed and ask to end the quest early even though the rules say you have to get to the stairs to get your reward(s).
The Rallying Horn, some lucky potions of speed, Swift Wind and of course hidden rooms full of monsters that Zargon activates when the alarm sounds are all part and parcel of making these quests much more interesting/fun rather than boring once you've found your goal.
Jumping pit traps becomes easy once you find the Rabbit Boots (but sadly only one of those in the quest packs by default...). I sell
the Whip as an alternative for pits at least.
Another homebrew rule is that when there are no monsters about, Zargon generously allows the Heroes to each make their full movement (12 squares unencumbered, 6 if they are Sir Ragnar, a hero carrying a chest, or anyone wearing Plate Mail) per turn instead of having to roll for it... but with my homebrew rules above, that brief respite without monsters is short lived...

I use the Evil Wizard Deck (which I added a few cards to, including giving my chosen monster doubled defense where appropriate... from drinking an evil potion) but even I recognize that having your health chipped away turn by turn from random events isn't very satisfying so I propose extra rooms of reinforcements laid out ahead of time that Zargon can use to jazz up certain quests like that. It's not wrong for the Heroes to have an easier quest now and then but like you said, it can get boring or anticlimactic in your group, so I understand.
In our group we always observed that potions "stack," and spells read like they say on the cards. Courage is indeed very powerful when used properly. Certain maximalist interpretations were clarified in the 2021 version (Line of Sight is what counts). However I made one tweak in our group to make it more useful... "at the end of his turn" meaning a Hero could kill all the monsters in his sight then use his movement to rush into the next group of monsters so the spell wouldn't run out. Technically it should end the moment he is out of LOS of monsters, which means bad guys can just run away to break the spell (guaranteed to raise groans from your heroes).
Consider the harder quests to come...
But you have certainly highlighted the weakness of the App and Zargon's limited options/AI imagination.