Charging a single-phase EV with three-phase power

So last month I bought my first EV (Škoda Superb iV PHEV) and it comes with single-phase charging. I immediately noticed that the provided home charger will only draw 8A from my 16A fused phase supply (the main fuses are 20A).

OK, I can understand that: somehow the logic finds that full 16A would load the fuse a bit too much or that the phase as a whole is incapable of delivering so much current and thus reduces charge current to the only lower available setting, which is 8A.

But I have run into many situations where having the battery charged in 3 hours instead would give me more electric range. e.g. you come home from work, but have to go shopping later in the afternoon. Naturally this makes me want to have an option of charging the vehicle faster, but I also have a condition of future-proofing my purchase since wallbox prices hover around 1000€.

So I see my options as thus:

1. Buy a charger that will be more adaptable to grid conditions and will charge at e.g. 14A if full 16 is deemed too much – should be relatively cheap.
2. Increase main house fuses and the particular socket fuse so that the charger will recognise it as 16A capable – this one comes with added monthly costs because of increased capacity, even if the actual consumption is ultimately the same.
3. Buy a wallbox that can fuse three-phases into a single phase.

I find option 1 a bit ridiculous: I already have a home charger and replacing it with a different one that would be a bit more adaptable seems somewhat funny.

Option 2 is risky and expensive long term. Risky because I have no idea what makes my home charger choose 8A over 16A. 25A main fuse & 20A socket fuse might not cut it.

So option 3 seems the best, especially if I want to future proof my investment (next car will probably be a BEV and will thus require a good wallbox). But I just can’t seem to find a wallbox that would match my requirements. I found this one, but AFAIU, it’s not future-proof as it ONLY does 3 phase to one phase conversion. It can’t become a 11kW three phase power supply for my next BEV.

Do I expect too much of my would-be wallbox? Or has someone run into the same issue as me and built a true adaptable three phase wallbox that can, when needed, also merge the phases to a single one? Alternatively, build my own with the help of my better electrically educated friends?

Edit: clarification on the limitations I’m facing:

Currently my house is connected to the grid via 3x20A main fuses. This costs 15€ per month just to be connected + actual power usage. Increasing main house fuses to 3x25A would increase the connection cost to 20€ monthly + actual power usage (not to mention the change itself which would be a few hundred €).

The wiring I’m using is fully under my control, and currently I’m using 2.5mm2 wires that should be able to carry 16A. Can replace easily if needed.

The general idea with option 3 is to actually lower the current demands on the phases: if I only need 16A (max charging current of my PHEV), that means a bit over 5A per phase… I do realise that even future proofing the wallbox with a 3-phase-capable one would introduce the same issue with a true BEV with 3-phase charging capacity.