Some games (like Super M) uses special audio chipset

Which audio are you talking about? MSX-MUSIC? As you said, audio is produced by an audio chip. ROMs are just software and data.

The MegaFlashRomSDSCC+ is a good choice, it already has Konami's SCC sound chip built in, which will give you great pleasure when playing many Konami games.
You decide which music add-on to put in the second cartridge port based on the game you want to play. In addition to the FMPac and OPL4 expansions, you can also enjoy the Yamaha SFG05 or the Neotron.

There is no all-in-one solution yet, only FlashRAM cartridges that offer more built-in sound chips, like the FlashJacks, the GR8Net or the Carnivore2.
I myself also like to use the MFR and then simply plug in the desired add-ons as needed.
If you want to experience G'n'G on an MSX2+ with SFG05 sound, you will of course quickly reach your limits without a slot expandor.
The game module and the GFX9000 expansion already occupy both cartridge ports. However, this is rather the exception.

I you speak about SMW. The sound is mainly MSX-Music and PSG. There is SCC sound, but only a little.

K. It seems when it comes to music expansion to guarantee you don’t miss one, you need to chain them in a row and hook each one to separate speakers and then have all the speakers cluttered on the table to guarantee a certain software output to that one so you don’t miss out.

That is for sure will not happen. I want advise then to one MSX music expansion cartridge that is compatible with super M ported for MSX here and most games posted here use that same chipset.

Well, normally you would use a mixer panel rather than the set-up that you describe .

For games just get the MSX-MUSIC and the SCC, those are the most relevant and you will have your bases covered. If you only play original games you don’t even need the SCC because they’re included in the cartridge. But otherwise you want a FlashROM cartridge with SCC support to play Konami games. The MSX-MUSIC cartridge is used by many other games from the late 80s and onward, you can find which ones do on generation-msx.

Specifically the Carnivore2 includes both SCC and MSX-MUSIC, so if you’re buying a new flash cart and want these sound chips as well, you might want to consider this as an all-in-one solution. Only thing to be aware of if you’re concerned about 100% authenticity is that these sound chips are FPGA emulations rather than originals, but probably that won’t matter to you.

All the other sound expansions on the market for MSX like MoonSound OPL4, SFG-05, Neotron, MMM, etc. are mostly aimed at people specifically interested in those chips and their music, either for playback or composition purposes, but they aren’t used in many games. Looking at your intended use I would advise you skip those for now, you can always get them later if you know what they are useful for and why you would want to own them. They’re a bit too expensive to get and then find you don’t use them. Also when you get them later separately you can spend more time to enjoy them individually, e.g. with music disks, VGM players and Sega SG-1000 games.