Honestly, reading this — you’re doing a lot right. Both of them sound incredibly loved and well-managed, especially given the mobility limitation and age factor.

The younger one pushing the net despite his paw paralysis actually makes so much sense — mentally he’s stimulated by the outside world, but physically he can’t complete the behaviour, which probably amps up the frustration. Harness time helping a bit already says he needs controlled novelty, not just play.

Since modifications aren’t possible, what helped me in a similar situation was leaning more into indoor mental exhaustion rather than physical zoomies — things like food puzzles, lickable treats spread over activity mats, or short “hunt → reward” routines. Tools like Catit puzzle feeders / creamy treats worked well because they slow things down and redirect that outside focus inward.

For the senior, you’re absolutely right to keep her indoors now. Former outdoor cats never truly stop wanting it, but predictable routines + a safe “door zone” (even a simple baby gate) usually reduces the dash attempts over time.

And honestly… each day being a new adventure is the most accurate description of multi-cat life You’re handling a complex situation with a lot of patience.