EVAL-LT8334-AZ - suggest optimal inverting sepic layout

Pity there's no suggested layout in the datasheet. I see you have a picture of the component placement from the Demo Manual though.

All I can suggest is to look at the datasheet for the LT8711 Micropower Synchronous Multitopology Controller with 42V Input Capability. It has layout suggestions for all the different topologies.

There's a SEPIC converter evaluation board and you can download the gerbers for it.

I have selected a non-coupled layout using

Cin              2pcs  4.7uF X7R 1206 - TDK CGA5L3X7R1
L1,2            2.2uH IHLP2525
D1,2           B340AF
Ccouple      2pcs 4.7uF X7R 1206 - TDK CGA5L3X7R1 ( top & bottom )
Ccatch        2pcs 0.1uF X7R 0402 - MUTATA GCM155R71
Cbulk          2pcs 22uF X7S 2220 - TDK C5750X7S2A

The -30V loop could be shorter.