Based on the variants below, I suggest that 8/2 7/2 works in Chuck's original position for two reasons:
1. White's blockade is weak enough that Blue can reasonably hope to escape his fifth wheel next turn instead of crunching further, and
2. the resulting forward position after 8/2 7/2 isn't bad.
  White is Player 2
score: 0 pip: 109  Unlimited Game  pip: 169 score: 0
Blue is Player 1  
XGID=ABACCcbbdbCbB:1:1:1:56:0:0:0:0:10 
Blue to play 56 
1.  Rollout^{1}  24/13  eq: 0.514 
 Player: Opponent:  31.62% (G:5.48% B:0.23%) 68.38% (G:30.65% B:1.32%)  Conf.: ± 0.010 (0.524...0.505)  [100.0%] Duration: 14 minutes 57 seconds 

2.  Rollout^{1}  7/2 7/1  eq: 0.617 (0.103) 
 Player: Opponent:  28.97% (G:4.00% B:0.10%) 71.03% (G:32.05% B:3.57%)  Conf.: ± 0.010 (0.627...0.607)  [0.0%] Duration: 12 minutes 23 seconds 

3.  Rollout^{1}  7/1 6/1  eq: 0.621 (0.107) 
 Player: Opponent:  27.41% (G:3.78% B:0.07%) 72.59% (G:29.67% B:2.56%)  Conf.: ± 0.009 (0.630...0.612)  [0.0%] Duration: 10 minutes 58 seconds 


^{1} 1296 Games rolled with Variance Reduction. Dice Seed: 271828 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.208.prerelease
  White is Player 2
score: 0 pip: 111  Unlimited Game  pip: 170 score: 0
Blue is Player 1  
XGID=ABACBAcbccbCbB:1:1:1:56:0:0:0:0:10 
Blue to play 56 
1.  Rollout^{1}  24/13  eq: 0.469 
 Player: Opponent:  32.30% (G:5.58% B:0.25%) 67.70% (G:28.45% B:1.52%)  Conf.: ± 0.010 (0.479...0.460)  [100.0%] Duration: 15 minutes 45 seconds 

2.  Rollout^{1}  8/2 7/2  eq: 0.540 (0.070) 
 Player: Opponent:  30.36% (G:4.37% B:0.15%) 69.64% (G:28.16% B:2.44%)  Conf.: ± 0.011 (0.551...0.529)  [0.0%] Duration: 11 minutes 32 seconds 

3.  Rollout^{1}  24/18 8/3  eq: 0.541 (0.072) 
 Player: Opponent:  31.74% (G:6.15% B:0.28%) 68.26% (G:34.82% B:1.57%)  Conf.: ± 0.010 (0.551...0.531)  [0.0%] Duration: 14 minutes 13 seconds 

4.  Rollout^{1}  8/3 7/1  eq: 0.546 (0.077) 
 Player: Opponent:  29.46% (G:4.06% B:0.09%) 70.54% (G:27.20% B:2.13%)  Conf.: ± 0.010 (0.556...0.537)  [0.0%] Duration: 11 minutes 04 seconds 


^{1} 1296 Games rolled with Variance Reduction. Dice Seed: 271828 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.208.prerelease
  White is Player 2
score: 0 pip: 109  Unlimited Game  pip: 154 score: 0
Blue is Player 1  
XGID=ABADBAcbbdbBbB:1:1:1:56:0:0:0:0:10 
Blue to play 56 
1.  Rollout^{1}  24/13  eq: 0.454 
 Player: Opponent:  30.64% (G:5.62% B:0.26%) 69.36% (G:21.91% B:1.36%)  Conf.: ± 0.008 (0.463...0.446)  [91.8%] Duration: 13 minutes 41 seconds 

2.  Rollout^{1}  24/18 8/3  eq: 0.463 (0.009) 
 Player: Opponent:  31.11% (G:6.54% B:0.30%) 68.89% (G:25.98% B:1.16%)  Conf.: ± 0.009 (0.472...0.454)  [8.2%] Duration: 11 minutes 50 seconds 

3.  Rollout^{1}  8/2 7/2  eq: 0.522 (0.068) 
 Player: Opponent:  28.35% (G:4.90% B:0.13%) 71.65% (G:22.69% B:1.61%)  Conf.: ± 0.008 (0.530...0.514)  [0.0%] Duration: 10 minutes 09 seconds 


^{1} 1296 Games rolled with Variance Reduction. Dice Seed: 271828 Moves: 3ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.208.prerelease