Like I said before, J-10s were tracked towards Matsu trying to get ROC SAM radars to light up. These happened days before the formal announcement.
Whether or not they're photographed by US or Taiwan aircraft is probably irrelevant, especially with the tons of internet photos, news articles, declared engine purchases, satellite photos, and even model kits being sold of the thing.
At least 100 aircraft is consistent to at least 3 confirmed regiments, plus one possible and two in the process of conversion.
to Simonov, J-10 payload is 7t. At least that is what the articles are saying. 4.5t is the internal fuel load, which is quite a lot for a single engined fighter. That means plenty of endurance to keep up a fight and use its afterburners often. Remember there are planes out there on paper, has a high TWR but achieves that with a low internal fuel weight, making this paper advantage a bit moot since you can't use the ABs that often.
Now reviewing again the pic of the older FTTC J-10s up there, looks like they got the white uplink on the back of the canopy now fitted. Looks like a field upgrade.