As an rsg high% runner, no. Currently the strat in high% is to get a desert and make a tnt cannon. To do this you need a desert spawn and in 1.18 I believe deserts have gotten rarer but they haven't changed at all. The Desert Hills biome might have changed, I'm not too sure, but desert temples only spawn in the flat "desert" biome. So you won't be getting desert temples on mountains. Considering tnt is the only way the get to y 420 a mountain spawn at y 200 is still useless.