How should I choose my spiral design to maximize output?

[Bosuonparedo]

From the starting options I can have a, b, c, d, or e higher. Should I just do e because it's the most expensive? What upgrades should I look out for for this?

[Kiara]

Usually B grants the most delta r increase, but ideally none of them as you'll be wanting to use a spiral such as Yellow&Red or Orange & Purple winding for the bonus it gives to battle, also I would advise focusing on progressing battle over main spiral as most of your power for main spiral will eventually come from battle.

[Jerry]

If you want some good r output later in the game, dotted blue (bonus for multiplier) is one to keep an eye on too; usually gets you further than yellow.
Beside that, as said above, yellow/red (better battle spiral value for idle online) and Pi (better z increase, good for offline phases) are spirals, you'll want to keep at hand.

[No]

when i respec I buy designs with a good passive bonus, plus the tier 3 purple/orange for combat.