But nevermind, ASM-One or Pro can open in RTG screens. There is a ScreenMode selector.
Devpac 3.50 was French only but 3.18 is international that's why i also use this one (aheem, well i'm french but i like keeping english language when speaking about coding).
And yes i also use 99% of my Vampire in RTG mode. But with MUI PSI tool it is possible to extend capacities of the system to push some apps on the other public screen (PAL or DblPAL for example). Is that useful ? i don't know, at least that's funny