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I am also a 2. For me, I keep the custodial risk spread among a few apps and keep the amounts small (50-100K). That said, in the future when LN payments become a standard, it will not be possible to keep only small amounts in custodial wallet. You will either have to choose to go non-custodial for most payments or build some trust with a custodial app.
That said, I'd look at your question from a perspective of Stacker News audience and your vision for the platform.
I'd venture a guess that a normal person who would use bitcoin stricly for payment and is not interested in anything else surrounding the technology would not come to SN. And I'd assume this is majority of the population.
So your audience is basically tech savy people with some outliers who are just interested in the idea of bitcoin and want to learn more before they have enough knowledge and stop coming. And of course now with the incentive to stack sats.
If the above assumptions are correct, then most people would have their own non-custodial solution, therefore making a non-custodial wallet would be an overkill.
The lndhub account idea might work, but if you still will have a custodial solution at the same time, the node liquidity maintenance issue still remains. So that does not make your life any easier, I don't think.
Perhaps a better way to go is to improve the way the custodial wallet functions. For example add scrub functionality like in lnbits to allow part of the funds to be transfered to own non-custodial solution.
At the end of the day, it all depends on what direction you want to take the business into. So, I'd look at what is your current end vision and then go from there.
Remember, there is beauty in simplicity.