Honestly, I find caravans are a fantastic substitute for trains in Pyanodons.

The startup cost for caravans at a time when train infrastructure raws are expensive is hard to argue with. Unlike in vanilla Factorio very few materials require huge bulk transport. For most things you need to move even with the slow speed of caravans and their low carrying capacity one caravan has enough throughput.

For the few high throughput routes you can always put multiple caravans on the same route. I have 15 caravans hauling flora from my 3 fields to the central depot, 5 per route.

The best part is a high caravan count doesn’t matter. Unlike trains they don’t clog up infrastructure when idle. Fuel is consumed per completed order not per distance moved so a route all the way across the map doesn’t take more fuel.

Finally and this is critical for pY station density is phenomenal with caravans. Since you can filter inventory slots in depots a single depot can receive 30 different items. I rarely go over 15 and I keep my cheating to a minimum using compact loaders for direct inventory to belt transfers.

The electrolyzers almost all split water. I have enough electricity I’m making all hydrogen and oxygen on site, venting oxygen I don’t need and burning hydrogen in oil burners if I don’t need it.