With Remus 1.80 I have build a nice Kickstart 3.9 1MB for my A1200D with next modules, libraries and devices ...
First ROM
ADD Modules/44.57_ROMUpdate(3.9bb2)/exec_45.20(A1200-A500)
ADD Blizkick/1MB_ROM
ADD Modules/40.68(A1200)/audio.device_37.10
ADD Modules/40.68(A1200)/battclock.resource_39.3
ADD Modules/40.68(A1200)/battmem.resource_39.2
ADD Modules/44.57_ROMUpdate(3.9bb2)/bootmenu_44.7(68020)
ADD Modules/40.68(A1200)/card.resource_40.4
ADD Modules/40.68(A1200)/carddisk.device_40.1
ADD Modules/40.68(A1200)/cia.resource_39.1
ADD Modules/40.68(A1200)/con-handler_40.2
ADD Modules/44.57_ROMUpdate(3.9bb2)/console.device_44.8
ADD Modules/40.68(A1200)/disk.resource_37.2
ADD Modules/MerlinKV/dos.library
ADD Modules/40.68(A1200)/expansion_40.2(A1200)
ADD Modules/BB4/FileSystem.resource
ADD Work2:Install/BoingBag3.9-3&4/Files1/L/FastFileSystem
ADD Modules/40.68(A1200)/gadtools.library_40.4
ADD Modules/MerlinKV/icon.library
ADD Modules/40.68(A1200)/input_40.1
ADD Modules/40.68(A1200)/intuition.library_40.85
ADD Modules/40.68(A1200)/keymap.library_40.4
ADD Modules/MerlinKV/layers.library
ADD Modules/MerlinKV/mathffp.library
ADD Modules/MerlinKV/mathieeesingbas.library
ADD Modules/40.68(A1200)/misc.resource_37.1
ADD Modules/40.68(A1200)/potgo.resource_37.4
ADD Modules/3.9-44.57_ROMUpdate(BB2)/ram-handler_44.24_NoBss
ADD Modules/40.68(A1200)/ramdrive_39.35
ADD Modules/40.68(A1200)/ramlib_40.2
ADD Modules/MerlinKV/romboot44_3
ADD Work2:Install/BoingBag3.9-3&4/Files2/Devs/scsi-A1200.device
ADD Modules/3.9-44.57_ROMUpdate(BB2)/shell_45.7
ADD Modules/40.68(A1200)/timer.device_39.4
ADD Modules/BB4/trackdisk.device
ADD Modules/MerlinKV/utility.library
ADD Modules/40.68(A1200)/wbtask_39.1
ADD Blizkick/ROMFixes_2.7
Extended ROM
ADD Others/ROMHeader/ROMHeader_E0
ADD Others/DummyCDstrap
ADD Modules/Blizkick/BPPCFix
ADD Modules/MerlinKV/datatypes.library
ADD Modules/MerlinKV/graphics.library
ADD Work2:Install/BoingBag3.9-3/Files1/libs/workbench.library
ADD Modules/MerlinKV/pfs3aio
ADD Modules/MerlinKV/SmartFilesystem
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ROM is plenty of space for that reason I have put the workbench.library inside.
ROM is really working like a charm.
Time to boot without HDD or floppy inserted is about 2-3 seconds.
Tested on 27C800 for single ROM setup and with M27C160/MX29F1615 (100ns) for four ROMs setup on my KS switcher.