Upgrading ships that use strategic resources

If this is true, this is a bug. I've never noticed this behavior though.

Does it really require you to spend it permanently?

The way I experienced it is, that the game requires you to have the ressources for building the ship new, but it won't increase the usage once you upgraded. Example: I ahve my arch dreatnought which requires 4 thullium and one elerium. Now I make a version with upgraded weapons (no additional ressource cost). In order to be allowed to upgrade I ahve to have the ressources I would spent on building the new version (4 thullium one elerium). However once upgraded the ship still only costs 4 thullium 1 elerium and I don't have double the ressources invested.

I guess mechanicly the game builds the new version (carries over exp) for which you require the ressources. Once upgraded the "old ship" however is gone, so it releases the ressources used in it. It is not an ideal or intuitive system, but you usually don't have the double the ressources invested.

This is the behavior I've observed as well- you need 1 extra set of resources for the duration of the upgrade per ship. Should it be this way? I think so, as it forces a more cautious approach to upgrading (or just changing the attacks/defenses in response to enemies) and prevents someone with too much cash from simply mutating their entire fleet of strategic resource-equipped ships at will.

The credit cost alone is usually deterrant enough to keep me from upgrading until late in the game when I ahve won anyways. I'd rather rebuild my fleet with new versions and sell my old designs to a minor faction.

You'd be pleasantly surprised at the minor upgrade cost if you have the same base ship design with just 1 weapon type or defense swapped.

But swapping one weapon or defense type is usually not enough of an improvement to be worth the cash and bother.

I just throw them in until they die and build better ones from scratch.

In my recent playthrough I have to pay ~400 for an engine upgrade (hyperdrive plus -> 2 ion drives) and ~800 for upgrading a medium ships weapons to the next tier. Given that I usually finance myself through trade and tourism, this is quite a deterrant. I won't upgrade 30+ ships at this price.

On the other hand with the new lvling mechanic if you have a "flagship" one thats survived 30 battles and has a some lvls behind it it would almost always be worth upgrading it

now if there was a way to upgrade hull size

Yes my point exactly.  I do not want to replace the ships I have all these levels on.   I want to just upgrade some parts that did not even use the strategic resources.  This is very silly that I must have a duplicate set of resources to upgrade it.  if the actual upgrade is not using any new resources.  it makes upgrading ships impossible or at least very difficult until late game when you basically have won any way.  this negates the entire idea of leveling ships if I must scrap them to upgrade them. or wait until late game when these ships are now useless, as why would I want a small or tiny hull in my late game fleet no matter what level it is.   it just does not have enough use to offset the logistics cost.

basically the time when ship levels make the most difference is early game when you have 5 or 10 small or maybe a few medium hulls, and very limited resources.  After I have a huge fleet late in the game with resources to spare the individual ships no longer have much meaning.  so at this time scrapping a ship to regain the resources and rebuild the ship is no big deal, but then you probably have excess resources anyway so it is a moot point.  This mechanic basically just makes leveling a ship with strategic resources a useless gesture.  I may as well just make basic ships that can level up and be upgraded as I get new tech, as the strategic resource ships will quickly become obsolete and just end up scrapped.