Hi, I just reached the Tier 4 research in my first exploration mode playthrough and would like to give some feedback.
Personally, I find it rather odd that the both the 5m Payload fairing and the 5m Engine mounting Plate are unlocked this late in the tech tree, considering the lack for 5m engines so far and that it seems a bit unrealistic to transport 5m trusses in a 3.75m payload fairing.
My personal suggestion for the unlock nodes of these two parts would be:
5m Engine Mounting Plate: unlocked in the "XL Methalox Tanks" node, as this is the first node that that unlocks 5m parts
5m Payload Fairings: unlocked in "XL Construction", as this is the node that currently unlocks the 5m nosecone
