I'm gonna need some more info on that.
1) Are all the saves from chapter11 part2?
2) Did you use JDMOD on those saves?
3) What kind of exceptions are you getting?
This is going to be true for all cheat mods for any type of game (No matter if it's a Renpy game, RPGM, Unity, Fallout, GTA or whatever). They don't necessarily play out the content for you, but you can raise/lower the stats and change the flags to help you get/avoid certain content or to make the game somewhat easier for you to play through (for example extra ammo, health, higher relationship points etc).
What you seem to be looking for is a gallery/scenery mod where you can just go to certain scenes, watch them and get back to where you were. While that is doable it just takes a different kind of work to achieve rather than what goes into a cheat mod (still thinking about it b.t.w.).
To answer your questions:
1) Are all the saves from chapter11 part2?
--- NOT sure .. there were some saves from before Ch11, some of which did load in Ch11-2 and some others didn't. Some i saved again while in Ch11-2, some others not.
2) Did you use JDMOD on those saves?
--- Not now but i may have loaded some of them few weeks ago as i had JDMOD installed.
3) What kind of exceptions are you getting?
--- Like the one i posted here before
Now.. OK i understand that the cheat mod is meant to be used while you play the game, not to repeat some scenes after you played it. That would indeed require a gallery mod. BUT:
1- The existent gallery mod is in my oppinion not ideal . I explained why.. beause it doesn't go to the scene you want to replay but to a time long before that scene (in many cases 1 full day earlier) and you must click a lot to get to the real scene that you want to see. In my oppinion that makes no sense.
2- I can see no reason why such a gallery mod (made in a way that it leads directly to the scene and not 1 day before) could not be combined with a cheat mode that would let you chose under which conditions you want to replay that scene..