Add an option for how many science packs per tier are used. In my opinion the tiers should be:
Base - Terrestrial Science packs
Tier 1 - Space science + "Advanced science"
Tier 2 - Deep Science + any upcoming science packs
Add an option for how many Base science packs are used per Tier 1 and one for how many Tier 1 science packs are used per Tier 2.
Of course this is just a suggestion so feel free to alter it to what you think is better.