Turns out that on the modded planet pelagos, you are unable to place inserters on the wooden platforms, which likely breaks progession on that planet.

The author of the pelagos mod confirmed that more long inserters has a change in the subgroup of inserters that results in them being un-placeable. They mentioned that they would attempt to fix this issue in a coming update, but I wanted to make you aware as well in case others ran into this issue.

Thanks for making this mod! It's fun having additional inserter options.

Thanks for the heads-up, looks like they just released the compatibility update a few hours ago.

I can't say that I understand why they're using the "subgroup" field to determine what kinds of inserters should be allowed on wooden platforms (that field is intended for use in sorting the crafting menu, surely there must be some other field they can use to filter out item types before resorting to something as obtuse as the subgroup)

And glad you've been enjoying it!

As a follow-up to this issue, the Pelagos mod author ended up accepting my suggestion here, which allowed me to add the Pelagos diesel inserters to the sorting list without breaking their functionality, implemented in v5.1.10