Proportions mod Version 2.5 is available from  
The Proportions mod web page.
Version 2.5:
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  Gameplay - Component Enhancement (i.e. "Mounts"):
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* Added Scale mounts. These make the size, cost and supply use of certain
  components directly proportional to the size of the thing they are 
  built on. Applies to components which naturally require effort and size
  based on design size: Stealth Armor, Scattering Armor, Emissive Armor,
  Scanner Jammer, Emergency Propulsion, Cloaking Devices.
  Note: Upgraded games from earlier Proportions Versions will find existing
  components of these types unchanged, but unable to be repaired until
  retrofit with scale-mounted Versions.
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  Gameplay - Armor:
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* Added a new type of standard armors - armor "plating", which is armor 
  covering the entire hull. Its size and cost is based on hull size (via the
  scale mounts). Its structure is not particularly high, but it is not hit
  first - its main feature is that it absorbs damage per non-armor-skipping 
  hit, at a level between armored structure and emissive armor.
  This represents a completely armored hull's ability to reduce the damage
  of every incoming hit without generally getting "shot off". It can be
  combined with armored structure to prolong this protection.
* Renamed standard armors as "armored structure". These represent armor
  reinforcing the hull, and work as before, though they now have a very small
  emissive effect.
* Stretched emissive armor to six levels, reduced its structure back near
  what it is in the unmodded game, and restored its "hit first" status.
  It offers the highest emissive ability, but can be shot apart fairly
  quickly. It can be combined with Ablative armor to increase its longevity.
* Added tech areas for specialized armor types (stealth, scattering, emissive).
* Adjusted costs of stealth, scattering, and emissive armor.
* Added three levels of "Scattering Shell" non-armored hull coating.
* Added Niche Reinforcement for obessive designers who must use every space.
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  Gameplay - Other:
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* Changed Graviton Hellbore damage type to Skips All Shields. They really
  needed enhancement, and it seems reasonable that shields would fail to
  interact with a gravitational weapon.
* Extended Tachyon Cannons to level V, similar to extensions to other heavy
  weapons in Proportions.
* Solved problem with SE4 not offering upgrades to Complexes and Megacomplexes.
  This required re-assigning Roman numerals to them, so now Complexes are
  IV through VI, and Megacomplexes are VII through IX.
* Re-defined Smart Bombs to new weapons which bypass planetary shields.
  There are missile and bomb Versions, with different multiple prerequisites.
* Added a new tech area for Tectonic Bombs, and extended them by two levels,
  adding cheaper low-tech Versions, as well as Small Tectonic Bombs, which
  inherit the abandoned damage types from the old smart bombs (because it
  was discovered that these would destroy entire cultural centers with 
  single hits once planetary shields were down). The old tectonic bombs are
  now harder to research, and require specific research rather than being
  always included in Stellar Manipulation.
* Quartered damage done by Neutron Bombs, for balance reasons.
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  Cosmetic:
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* Added "B" code to Standard Base Mount, as a visual indication that one
  has remembered to use this to get the free +30 to-hit on space station 
  weapons.
* Removed all trailing spaces from Math.txt design names file.
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  Design Upgrade Improvements:
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* Thanks to Gimboid's Component Editor, it was easy to spot a number of 
  components which would change type during an automatic design upgrade.
  Thanks also to those who pointed out some continuing problems with
  certain components. I think I've now done them all. 
  The changes are as follows:
* Computer Pilots no longer upgrade to Master Computers.
* Shield Generators no longer upgrade to Phased Shield Generators.
* Fighter shield generators no longer upgrade to AFV ones (!).
* PD Beams no longer upgrade to phased polaron beams.
* Allegiance Subverters no longer upgrade to short-ranged Versions.
* Massive Shield Depleters no longer upgrade to short-ranged Versions.
* Massive Ionic Dispersers no longer upgrade to short-ranged Versions.
* Small Electric Discharge no longer upgrades to surface Version (!).
* Small Acid Globule no longer upgrades to surface Version (!).
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  AI:
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* Ukra-Tal would never research rock planet colonization (fixed by oleg).