I went through this search 20 years ago. Back then I had finally decided for a Kurzweil SP-76: 76 comfortably semi-weighted keys, roughly 10 kg, fit nicely onto the backseat of any car, 32 simple on-board sounds with 32 programmable preset slots, and two fully programmable ribbon strips.
I connected it to a Kurzweil K2600r, also roughly 10kg. This way I had a very portable and back-friendly setup for the stage during 10 years. I later sold the master keyboard for a Kronos 61. Not the best decision for home practice but a more compact one for the stage.
If I had to decide today, I would go for a Clavia Nord Stage 3/4 Compact or, if it were a few kg lighter, a Korg SV-2 73.
Why not 88 hammer-weighted keys? For modern piano play (blues, rock, pop, etc), 73-76 keys are most often enough.
In addition, semi-weighted keys are a decent compromise. Piano-action keys tend to come in heavier boards and are less adapted to be played with organ and synth sounds. I once owned a Kurzweil K2600X with 88 fully-weighted keys during 6 months -> 33 (!!) kg, it was a real eye-opener to me, no matter the comfort of this wonderful synth. I sold it as soon as possible.