The closer a red base is to the 2 GG’s (base 1 and 2), the worse. I think that having other colored bases than yellow on 5’ tail part, closer to the starting GG’s is worse than if they are more distanced. I have regularly seen red in particular and green to pair up with other parts of the design. Having many strong bases in line, means that this first part of the sequence will be more likely to find somewhere else juicy, pair up and stay there, instead of becoming tail and stay single.
I will like a strategy that says:
-3 if next to the GG’s
-2 if one away from the GG’s
-1 if two away from the GG’s
Half penalty for the greens.
Quarter penalty for blues
And half penalty for the boost spot. Sometimes a red is actually beneficial there.