The whole point of doing these games is to see what result is under IJS. You can still judge the quality of elements and PCS and apply the IJS principles. We don't have to call levels on elements unless they miss the element and it becomes invalid. We have had to run competitions at my rink like that when we don't have a TS.
Having just Choreographic Spirals will actually make the calling of spirals easier. I think go for quality in terms of how well it is performed rather than worrying about if they are held for however many seconds. Just recognise they have done a spiral sequence.
I am with gkelly. I am now so far removed from judging 6.0 for these kinds of programs I don't want to go back. But also people have found these exercises really interesting and given them a great understanding of the judging system. And they learn how hard it is to be a judge.
In answer to marking elements invalid, you can do it manually in the system as you do the datat entry. No problem there.
If someone wants to organise a judging game under 6.0 be my guest. Just remember though if you want to get a result, you need to be able to do the calculations to get the result and that is easier said than done. I have no clue how you do it unless you have the relevant software.