The lack of liquidity that exch has is due to them not being able to supply enough coins. They already have the buyers that are willing to pay 5%+ in fees and who eat up all the available supply in less than 24h, so what they need more is monero sellers to sell on exch (instead of some other places).
This (still) makes me believe Monero is
highly undervalued.
How do you incentivise people to sell on your exchange? By offering better prices.
That's not really possible on an instant exchange. On "regular' exchanges, the market decides the price. On eXch, it's based on other regular exchanges. It wouldn't dare predict what would happen if eXch were to offer a higher price for Monero than other exchanges. It may lead to all liquidity on those exchanges being eaten by arbitrage traders, more Monero flowing into eXch, and the price spiraling upwards. Either way, I don't think it solves the liquidity problem. But that's just my own speculation of course.
The volume of XMR over the last 24 hours for eXch is 6776.91 .
I have the impression that eXch no longer really suffers from liquidity problems with XMR.
At the moment, XMR-reserves are less than 1% of the 24h volume. That confirms what has been posted before: any Monero that gets added quickly gets sold.
Monero on a CEX is not the same as Monero in your own wallet

Nice to start the thought process. The "market" doesn't decide anything, it's simply market participants (usually market makers) with an incentive that decide the price of any asset indefinitely until some other big players decide to join in.
If liquidity moves over from CEXs to exch, then how is exch still having liquidity problems (to supply new coins)? What happens is that instead of leechers sucking the 5% profit from exch (because of supply problems), this gets into exch's pockets, while other market participants will profit off the sell on exch/buy on cex arbitrage.
Sounds like a win win.