I have encountered what may be a rare incompatibility issue with JRCONFIG. Space Quest I v1.0X is the first version of an AGI game that is truly DOS-compatible. I have been told that the next version, v.1.1A, works fine in a PCjr. without any memory manager needing to be loaded, but 1.0X requires a memory manager. I confirmed that v1.1A works with no memory manager as Sierra advises in its AGI Reference Card.
I tried 1.0X with both JRCONFIG v3.10 and 2.14 and they would crash after the name entry screen. The PCjr. Memory Options disk does not work with my jrIDE card, it complains that it cannot find the settings for the dipswitches. (The IBM driver works with 86Box and gets the game running when using the /E switch). The Microsoft Booster memory driver, memory.sys, does work with the jrIDE card and allow the game to run when configured as follows :
device=memory.sys /v:32 /s:0
This sets the video memory to 32K and does not make a RAM Disk. Only then will Space Quest I v1.0X get past the name entry screen and actually allow you to play the game. You are better off playing a later version, this early version chugs in a PCjr. like it is running code out of slow memory.
I don't know why JRCONFIG.SYS would be incompatible where IBM and Microsoft's drivers are compatible. I disabled RAM Drive creation with the 2.14 driver and it still did not work.