Second part is up.

?-5 is easy.
?-6 requires Lilac in a group and another group to be slower than the rest.
?-7 requires Lilac in a very fast group and another very slow group. Alternately 2 at the top camp without Lilac can work (party 1 needs to get to switch node first, party 2 very fast), but the middle camp requires more RNG luck.