There are lots of solutions if you were willing to replace the wall switches. Or at least cover them.
If you are in the US, then, for example, the Lutron aurora dimmer fits over your existing switch. I have 4 of these in my own house and they work great. They are instantly understandable to guests, but they keep the hue bulbs always powered.
There is another option if you are in the US, which is to use a Fibaro dimmer 2 behind the existing switch, tie off the circuit so that the bulbs always have current, and attach the existing switch to the second input. This input does not control the current. It just sends central scene command numbers to the hub which can then tell the bulbs what to do.
If you’re in the UK, it’s much more complicated, so we do need to ask what country you are in.
Anyway, those two would be the easiest for what you’ve described. Noticed that the difference between what I’m talking about here and what you mentioned in your first post is that although you are using a Fibaro, you are not using the input of the Fibaro that controls the current (input 1). You are going to use the input that only sends scene commands.
Oh, one more thing… In no case can you use the Fibaro with an existing analog dimmer.
So if your current switch is a dumb rotary dimmer, you’re out of luck. The physics are just too different.
But if the current switch is a toggle or a rocker, you’re fine.