J-10CE will be a lot more costly for PAF than simply acquisition and equipment costs. PAF does not support the WS-10 engine and how many units of J-10CE will be required before it makes sense to develop the supporting crew, tools, parts, equipment, and infrastructure?
Both PAF and China would likely prefer working on getting the PAF a foot in the 5th gen door ASAP. India will probably eventually be buying Su-57 in the coming years/decade or F-35/Euro 5.5 gen in the coming decades. They're very confident about AMCA surpassing all but Raptor/Lightning II (lol) and being delivered some time around 2030. Anyway you feel about all that, PAF probably needs to think about 5th gen to counter Rafale and future IAF 5th gen induction instead of playing around with J-10CE.
JF-17 upgrades are a natural thing because IAF does still have a lot of older fighters to counter and numbers are still important. JF-17 is the affordable, domesticated numbers filler and upgrading even older blocks with more affordable AESA radars and better missiles, improve their performance with the most effective return on investment. But these don't necessarily counter the superior IAF numbers and soon to be superior equipment (Rafale full induction and familiarisation). The Indian economy is just so much larger than Pakistan's, an arms race and attrition confrontation isn't going to go Pakistan's way. China's support with financing and weaponry is absolutely critical if Pakistan is going to ensure ant Indian aggression will be responded with enough cost to make them hesitate. This has been how Pakistan have kept the situation and the only sensible way to approach the security problem i.e. you can't outspend the Indians lest Pakistan go broke from overspending on arms.
So J-10CE being considered in this context doesn't make sense. It doesn't add considerable capability improvements over Rafale if any at all and it's going to be unduly expensive for either Pakistan or China (whoever foots some or most of the bill). That effort, money, and time could be better spent developing and fielding a convincingly superior fighter into PAF which "needs" to be done sooner rather than later. Or clever diplomacy to de-escalate conflict with India but quite unlikely with the Nazi wannabes RSS and BJP in power (they even have their own Seig Heil solute gesture
).