Here are some positions that help.
First is a holding game down in the race that would be a borderline pass. We should expect that cube efficiency is very low since most wins come from a crushing hit. The RO does indeed show that but lower levels show XG does not use this concept.
Results are shown for 2-ply, XG ++, and RO. The difference between cubeless and cubeful equity for the RO is .036 and it shows a pass with DT equity of 1.042. The difference from XG++ is .046 and it shows a pass with 1.026 DT. If 2-ply is used the cubeless equity of .552 is essentially correct but instead the difference between cubeless and cubeful is .081. XG on 2 ply mistakenly thinks it is a solid .941 take due to drastically overestimating the cube power.
What follows is a race where 2-ply thinks the cubeless equity is .551. The difference between cubeless and cubeful is .074 and 2 - ply thinks it is a .954 take. The RO shows very close results.
Summarizing 2 ply does a great job at getting the win percentages correct for both the race and the holding game position. It does a great job at factoring cube power for the race and 2 - ply gives a very good value for the take equity and does a poor job at factoring in cube power for the holding game position (seemingly treating it just like a race?) and gets the take equity wrong by about .101.
This already shows that trying to emulate OTB what XG does may not be the best goal.
        
 
        
 | | White is Player 2
score: 0
pip: 117 | | Unlimited Game | pip: 86
score: 0
Blue is Player 1 |
|
| XGID=-BABBbBBB----Ba--bbbbbb---:1:-1:1:00:0:0:0:0:10 |
| Blue on roll, cube action? |
| Analyzed in 2-ply | No redouble | Redouble/Take |
| Player Winning Chances: | 77.06% (G:2.40% B:0.01%) | |
| Opponent Winning Chances: | 22.94% (G:1.29% B:0.08%) | |
| Cubeless Equities | +0.552 | +1.103 |
| Cubeful Equities |
| No redouble: | +0.471 (-0.471) | |
| Redouble/Take: | +0.941 | |
| Redouble/Pass: | +1.000 (+0.059) |
| |
| Best Cube action: Redouble / Take |
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 117 | | Unlimited Game | pip: 86
score: 0
Blue is Player 1 |
|
| XGID=-BABBbBBB----Ba--bbbbbb---:1:-1:1:00:0:0:0:0:10 |
| Blue on roll, cube action? |
| Analyzed in XG Roller++ | No redouble | Redouble/Take |
| Player Winning Chances: | 77.86% (G:1.73% B:0.02%) | 77.86% (G:1.73% B:0.02%) |
| Opponent Winning Chances: | 22.14% (G:1.57% B:0.04%) | 22.14% (G:1.57% B:0.04%) |
| Cubeless Equities | +0.559 | +1.117 |
| Cubeful Equities |
| No redouble: | +0.513 (-0.487) | |
| Redouble/Take: | +1.026 (+0.026) | |
| Redouble/Pass: | +1.000 |
| |
| Best Cube action: Redouble / Pass |
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 117 | | Unlimited Game | pip: 86
score: 0
Blue is Player 1 |
|
| XGID=-BABBbBBB----Ba--bbbbbb---:1:-1:1:00:0:0:0:0:10 |
| Blue on roll, cube action? |
| Analyzed in Rollout | No redouble | Redouble/Take |
| Player Winning Chances: | 78.06% (G:1.42% B:0.02%) | 78.06% (G:1.42% B:0.02%) |
| Opponent Winning Chances: | 21.94% (G:1.85% B:0.05%) | 21.94% (G:1.85% B:0.05%) |
| Cubeless Equities | +0.557 | +1.113 |
| Cubeful Equities |
| No redouble: | +0.521 (-0.479) | ±0.003 (+0.518..+0.524) |
| Redouble/Take: | +1.042 (+0.042) | ±0.007 (+1.035..+1.049) |
| Redouble/Pass: | +1.000 |
| |
| Best Cube action: Redouble / Pass |
| Rollout details |
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
|
| |
| Double Decision confidence: | 100.0% |
| Take Decision confidence: | 100.0% |
| Duration: 3 minutes 52 seconds |
eXtreme Gammon Version: 2.10
  
 
| | White is Player 2
score: 0
pip: 94 | | Unlimited Game | pip: 84
score: 0
Blue is Player 1 |
|
| XGID=---BBCCCB----a---bcccc----:1:-1:1:00:0:0:0:0:10 |
| Blue on roll, cube action? |
| Analyzed in 2-ply | No redouble | Redouble/Take |
| Player Winning Chances: | 77.53% (G:0.00% B:0.00%) | |
| Opponent Winning Chances: | 22.47% (G:0.00% B:0.00%) | |
| Cubeless Equities | +0.551 | +1.101 |
| Cubeful Equities |
| No redouble: | +0.477 (-0.477) | |
| Redouble/Take: | +0.954 | |
| Redouble/Pass: | +1.000 (+0.046) |
| |
| Best Cube action: Redouble / Take |
eXtreme Gammon Version: 2.10
| | White is Player 2
score: 0
pip: 94 | | Unlimited Game | pip: 84
score: 0
Blue is Player 1 |
|
| XGID=---BBCCCB----a---bcccc----:1:-1:1:00:0:0:0:0:10 |
| Blue on roll, cube action? |
| Analyzed in Rollout | No redouble | Redouble/Take |
| Player Winning Chances: | 77.44% (G:0.00% B:0.00%) | 77.44% (G:0.00% B:0.00%) |
| Opponent Winning Chances: | 22.56% (G:0.00% B:0.00%) | 22.56% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.549 | +1.098 |
| Cubeful Equities |
| No redouble: | +0.479 (-0.479) | ±0.002 (+0.477..+0.481) |
| Redouble/Take: | +0.958 | ±0.004 (+0.954..+0.961) |
| Redouble/Pass: | +1.000 (+0.042) |
| |
| Best Cube action: Redouble / Take |
| Rollout details |
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
|
| |
| Double Decision confidence: | 100.0% |
| Take Decision confidence: | 100.0% |
| Duration: 1 minute 12 seconds |
eXtreme Gammon Version: 2.10