No disrespect to altcoins but are you saying that insight is pretty *stable* for bitcoin? Or do we have similar issues with bitcoin as well?
I think it's okay to state that Insight is stable for Bitcoin and safe to use as it's intended for Bitcoin in the first place and Bitpay's business after all. Altcoin support is basically a bunch of hacks that work for some and doesn't for others. POS is basically not supported at all. That being said, they are moving from Bitcore to Bitnode for the fundamentals of their products. I didn't have a look at it, but the way bitcore has evolved over time, altcoins might be a definite no-go with this explorer.
The issue I have is probably specific to the version I use. If I take a more recent version in my case, it's back from scratch and the success rate might just be as miserable.
Yes POS isn't included but its not on bitpay to make sure it is and as far as other alts go it really isn't all that hard...
https://github.com/bitpay/bitcore/blob/master/lib/networks.js#L115 or you could clone the repos from digibyte and follow along with the commits we have pushed
https://github.com/digibyte/insight You will need to make changes to the 3 main repos (URL's can be found in package.json) Insight, Insight-api and bitcore.
Also not sure what you mean about them switching to 'bitnodes' as a large majority of bitpay's projects are based around bitcore.
All things being equal Insight is probably about as hard to setup for a new coin as Abe is but Abe has a nicer API in my opinion.
If you are looking for an explorer thats relatively easy to setup and supports a vast amount of coins then check out
https://github.com/iquidus/explorer It grabs all the required transactions via RPC so its slower to sync than Insight/Abe and you need to make sure txindex=1 is in your coins conf.
Cheers.