In Romulan Armada Unity, page 36 under the Drones section, it says:

PDF says August 2017 Romulan Armada – Version U1.0 in the footer but I downloaded this on October 17, 2018, so I assume it is the most recent one.

Wanted to have version 1.1 of the Starmada Unity Rulebook ready for release today, but likely won't be until later this week. In the meantime, here's the new page 25 which includes changes to range-based weapon trait modifiers and a revised seeking weapon formula.

Keep in mind that these changes are minimal. There are some combinations that are radically different (e.g. Crn/Sct) but I'm really just doing this because I want to be as close to "correct" as possible.

I don't see a need to go back and redo ships that have already been created. For example, even if every single one of your weapons had the Dfs/Tls combination (one of the largest changes) the final Combat Rating would only be off by about 10%.

To change your v1.04 Drydock to compute Seeking weapons accurately, do the following:

1) Unprotect the WEAPONS tab.

2) Unhide alll rows.

3) Insert a column between BA and BB.

4) Enter the following in cell BB2:

=IFERROR(ROUND(B2*IF(B2<0,-1,1)*C2*VLOOKUP(D2,TABLES!A:B,2)*IF(E2=0,0,(E2+0.25))*IF(F2=0,0,(F2+0.6))*PRODUCT(R2:V2,AB2,AP2),1),0)

5) Enter the following into cell BC2:

=IF(B2<0,(BB2*C2*ABS(B2)*0.19)^0.5,0)

6) Enter the following into cell L2:

=BB2+BC2

7) Fill the new formulas down to row 101 in columns L, BB, and BC.

8) Hide columns M:BF.

9) Protect the tab.

Okay, a few problems.

Once I got home I did everything as you said, but kept getting odd things happening. First, the BSUR was always some multiple of what it should be, and second, the drop-down lists weren't working. I tinkered for a while and think I've got the answer

Step 4:
a) the formula should be inserted into cell BA2 instead of cell BB2
b) the formula should read (R2:V2,AB2,AO2),1),0) instead of (R2:V2,AB2,AP2),1),0)

(The column AP was, I think, for the ordering of the weapon traits, as it kept changing between a value of 1 and 5)

Step 5:
a) the formula should be entered into cell BB2, not cell BC2.
b) the formula should read (BA2*C2...), not (BB2*C2...)

(this is as a result of inputting the main weapon formula into cell BA2. The reason for this is that column BC is for the drop-down lists in the ship spreadsheets--I think)

Step 6:

the formula entered into cell L2 should read =BA2+BB2 (this is as a result of the previous 2 steps)

I haven't done that much with Excel before, and certainly not on the scale of this, so YMMV. However, it calculates the example seeker weapon correctly, it calculates normal weapons correctly, AND it allows all weapons to be selected from the drop-down lists in Ship sheets 1 through 5. I must further state that I'm working from a version of Drydock v1.03 that I updated with the minor changes to v1.04, so it might be that v1.04 was different...

Because in order to balance, say, a range-18 Carronade weapon with a range-12 non-Carronade weapon (which are, after all, the same thing range-wise), there needs to be a fudge factor applied at the end. Consider this:

Weapon A: 6-12-18 (1×4+/1/1) Crn = 7.2
Weapon B: 4-8-12 (1×4+/1/1) = 6

Weapon A costs more because, although the weapons have the same effective range, its average to-hit across that range is better (56% vs.  44%). The same is true when applying Sct to the mix:

Weapon A: 6-12-18 (1×4+/1/1) Crn/Sct = 18
Weapon B: 4-8-12 (1×4+/1/1) Sct = 11.4

Here, the difference is greater because, in addition to being more accurate, Weapon A does more average damage (2.33 vs. 1.67).