K, i'm talking about first thinking about your planned end-use of previously cooked food. That influences the selection of your finishing method which you thankfully demonstrated. To be done competently it required your prior thought and know-how in making the best choice for your intended food product use.
I haven't seen any recipes calling for charring, but i don't often use them. For charred chicken, which i consider to be aggressive or prolonged searing, - as in going beyond achieving the Maillard reaction, you could likely be applying enough heat to sufficiently reheat your cooked chicken.
You may already be aware that the production of potentially harmful mutagens can be significantly increased with prolonged heating at temperatures over 300F/150C, - as in charring. With every subsequent 50F increase in temperature the production of mutagens doubles.
You might find it useful to know the folks at America's Test Kitchen recommend enhanced browning by using a pinch of baking soda with a thin film of a corn syrup, or similar source of fructose or glucose. Just a little now, i don't mean you should make a glaze. The result is an enhanced roast meat flavour and aroma without the associated bitterness of burned meat.
Lately a lot of SV cooks are using the old grill cook's trick of using mayonnaise on food to enhance browning.
If you plan to reheat cooked food by using a microwave oven, reheating by using the SV technique would be redundant.