Fairly certain the ST material nodes last map were heavily camped by a small group of people as you've said, and allot of the materials brought over from last map have still not be made or used for things. The implementation of giving lore materials out as a reward for people during events has only just begun I believe.
Hiding the location of the node does not matter once it is found, the length of a cooldown for the node is intended to slow the amount of material circulating to players not give time for other people to access it.
Seemingly lore materials have a 'rarity' which is basically summed up with its usefulness in combat like in most games, so that the more potent materials are very few and not particularly spread.
Certainly alchemy nodes are well implemented but I'm also quite sure that there are a few of those nodes which are also classed as 'rare' and are few and far between which are often taken on cooldown due to their usefulness in the potions people want for combat.
The change that I'd like to see and what I believe everyone should be wanting in particular is lore material nodes for things that are lower in popularity due to the disparity in strength it has in combat, so players can have an easier time and introduction into lore materials themselves and have the benefit of being able to interact with it on their character.
Additionally, perhaps give the current system time. I don't think the current system puts such a heavy burden on the most populated team, and I'd hazard a guess that giving out lore materials for events is likely as simple as asking Squak or looking at a list.
My real suggestion is to just flood the 'market' so every crp encounter every character has an arsenal of boomsteel to smack eachother with :)