I've been looking through the designs in the Bourbaki Basin and I see a lot of people using battlecruiser as a separate size of ship. Not that there is anything wrong with that , but I've always imagined it being like our own history where a BC is just a thinly armored BB with cruiser speed.

So given the following two designs, one for a BB, one for a CA, I present my vision of a BC (see design three). It is just as fast as the cruiser but has the size and armament of the BB, protected as a CA. Again, as in history, I doubt the politicians and Admirals would be able to resist throwing it up against enemy BBs. They see a 250KmT ship (Hull size 12) and say “hey they must be equal.”

Ponderous Class Battleship of the Surmised Space Service   ( 442 )
Mass: 237.5 KmT, Crew: 708, TL:   E:0  W:0  S:0  Q:0
Hull: 12 11 10 9 8 7 6 5 4 3 2 1
Engines: 4 3 2 1
Shields:  5 4 3 2 1
[α] Blaster [5/10/15, 4+ 2/1/1]
ABC, ABC, ABC, ABD, ABD, ABD
[β] Laser Cannon [3/6/9, 3+ 1/1/1]
AB, AC, BD, CE, DF, EF
[γ] Defensive Laser [2/4/6, 3+1/1/1]
AB, AC, BD, CE, DF, EF
Hyperdrive [O], Anti-Fighter Batteries [O], Electronic Countermeasures [O], Spinal Mount (9/18/27) [O]
1[Hα], 2[Eβ], 3[Hγ], 4[S], 5[H], 6[Q]

VBAM Stats
Cost: 13, Maint: 5/2, DV: 12, AS: 8, AF: 5, CR: 7, CC: 3, Base: 0, Spd: 4, Warp: Y, Notes:
Starmada Imperial Stars Edition v1.7

Dependable Class Cruiser of the Surmised Space Service   ( 176 )
Mass: 135.9 KmT, Crew: 444, TL:   E:0  W:0  S:0  Q:0
Hull: 8 7 6 5 4 3 2 1
Engines: 6 5 4 3 2 1
Shields:  3 2 1
[α] Blaster [5/10/15, 4+ 2/1/1]
AB, AB, ABC, ABD
[β] Laser Cannon [3/6/9, 3+ 1/1/1]
AB, AB, CE, DF
[γ] Defensive Laser [2/4/6, 3+1/1/1]
AB, AB, CE, DF
Hyperdrive [O], Anti-Fighter Batteries [O], Electronic Countermeasures [O], Spinal Mount (8/16/24) [O]
1[HQ], 2[Eα], 3[Hβ], 4[Eγ], 5[H], 6[S]

VBAM Stats
Cost: 9, Maint: 3/2, DV: 7, AS: 7, AF: 4, CR: 6, CC: 3, Base: 0, Spd: 6, Warp: Y, Notes:
Starmada Imperial Stars Edition v1.7

Hood Class Battlecruiser of the Surmised Space Service   ( 270 )
Mass: 251.1 KmT, Crew: 693, TL:   E:0  W:0  S:0  Q:0
Hull: 12 11 10 9 8 7 6 5 4 3 2 1
Engines: 6 5 4 3 2 1
Shields:  3 2 1
[α] Blaster [5/10/15, 4+ 2/1/1]
ABC, ABC, ABC, ABD, ABD, ABD
[β] Laser Cannon [3/6/9, 3+ 1/1/1]
AB, AC, BD, CE, DF, EF
[γ] Defensive Laser [2/4/6, 3+1/1/1]
AC, BD, CE, DF, EF
Hyperdrive [O], Anti-Fighter Batteries [O], Electronic Countermeasures [O], Spinal Mount (9/18/27) [O]
1[Hα], 2[Eβ], 3[Hγ], 4[S], 5[H], 6[Q]

VBAM Stats
Cost: 11, Maint: 5/2, DV: 9, AS: 9, AF: 5, CR: 7, CC: 3, Base: 0, Spd: 6, Warp: Y, Notes:
Starmada Imperial Stars Edition v1.7