Then how about this?:
After 2 consecutive passes, the players should mark dead stones. The players should not need to or be able to mark empty intersections. The players can only toggle the status of strings of stones.
During this marking phase, the scoring system does not provide any pre-markings of dead stones, but it does display a 100% accurate score (including a clear marking of all territory intersections on the board), given the current markings of dead stones by the players. So there should be no surprises on the scoring result when both players agree about all dead stones during the marking phase.
If there are any open borders, the score presentation during the marking phase reflects that, so attentive players can resume to fix those. One could say that the system is assisting the players by showing the score during the marking phase, but I think this is quite low level assistence, because counting during the marking phase is simply using floodfilling, which does not require any tactical go skills. It does require the system to understand seki to score the game correctly when the game is played under Japanese rules. This is complicated, but OGS can use the KGS algorithm, which is very robust and its source code is available.
The system may provide some additional time-saving assistence by marking all other stones dead that can “see” friendly dead stones and marking stones alive that can “see” dead opponent stones. Such features also don’t require tactical go skill. It’s just basic logic that can be programmed into a “dumb” algorithm, perhaps some sort of Wave Function Collapse algorithm.
When a player clicks the “agree” button to finalise the marking phase, the system should be completely clear on what they agree to. To avoid mishaps in the finalisation of the marking phase, there should be a short agreement cooldown period after being shown the last marking change (during which time any previous agreement is cancelled).
If the players cannot reach an agreement about dead stones, but they also both don’t play any moves after resumption (so they enter a resumption-pass cycle), the game ends then and there and the game is scored by an autoscore algorithm that uses an AI, possibly @Feijoa’s algorithm. I think this feature would make the scoring system better than KGS’s.
I think such a scoring system would help beginners who don’t understand life & death, and it would also provide a fair result for victims of score cheating. Still, it would avoid giving tactical hints to the players, violating OGS’ ToS.