Given your already using/familiar with Ableton, Id say a Push2 is the ‘obvious’ step, it’ll give you some hands on control that you want - and gives you some interesting options to develop into …
i kind of partially agree with this , and partly disagree…
out of the box, of course it describes a certain flow…
but its actually very programmable, at a simple level with max4live, or beyond by writing your own applications.
Ableton published a full API document for it - so Ive got the push2 working with a rPI and Organelle , and also hooking up to a eurorack modular via Bela Salt - I admit thats quite technical , but creating your own Max4Live devices is much more approachable - and you could “easily” write things that moved outside the normal ‘workflow’ and made it less linear.
I think, reality is to get what you want, your going to end up investing time and money in this, and your choice is which you do you want to spend more of
I love the push2, there’s little on the market matching its display (certainly at the price point)
but if you want a cheaper option…
look at the push 1 (used) , its actually easier to program, and gives many of the benefits.
the big disadvantage i see for you , is not being able to display waveforms nicely, which really helps editing - but your can do this by ear.
( i think push1 is very underrated for non-ableton stuff, and as the used prices are dropping becoming really attractive)
cheaper than that, there are loads of controllers, launchpad, faders - again link these up with max4live and you could create a really interesting custom environment within Ableton.
I think also it’d be useful to ‘evolve’ your approach slowly,
a push would allow you to get some benefits immediately,
then slowly start learning and customising with Max4Live in ‘baby steps’,
as you get familiar, you could then utilise than max knowledge to start looking at building an even more customised system in Max.
all still using Push and any other controllers that you decide to add along the way.