the mod still has the low heat exchanger item, but currently it is useless now as there is now no low tier heat generation options, until you get nuclear reactors.
Maybe readd the original solid and liquid heaters for early game?

Actually there is a enable as space age setting, but it does not appear to work correctly

The low heat exchanger isn't really meant for power generation in Space Age, it ties into another mod of mine called Steam Cracking that changes the oil cracking recipes to require steam again (and removes a production step on Vulcanus as a side effect) so you can save some energy. I'll look into the setting issue, seems I forgot to include a locale key for it.

Okay, so on review the setting was never implemented, the mod just adjusts the stats for the power plants automatically when Space Age is installed. This is working as intended as the heating tower is pretty ridiculous compared to any vanilla burner and needs to be for its intended purpose on Aquilo. I'll remove the mod setting in the next version since it's not used for anything.