after the planet discovery tech there should probably be trigger tech:
trigger: sand, unlocks: the 2 recipes currently unlocked by the planet discovery tech

trigger techs were exactly introduced to avoid an issue with techs that are currently possible with Moshine: nothing prevents researching deep into the planet techs without being able to use them. the trigger tech I mentioned should be right after the discovery tech and gate the mentioned recipe but also the 3 following recipes that are currently directly following the discovery tech (glass, magnetism, silicon).

maybe even more trigger techs would make sense, but this is the most obvious example and issue right now.

added something like that to my planet compat mod

https://mods.factorio.com/mod/xor_planet_tweaks_compat

EDIT: your latest change to move the recipes from the discovery tech to their own techs is an improvement, but still doesn't solve the issue of the missing trigger tech in between. I updated my mod accordingly for your new techs.