I have an idea how to run the same app parallel with different BOINC versions.
What does it mean?

I will setup all old non NCI apps again.
Example:
old app: max 7.4.11 -->non asic plan_class
new app: min 7.4.12 -->asic plan_class

You have the decision what config do you want to run. I will test it first with cgminer test app if its working.

-Reb

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