If you're prepared to take drastic steps, get a systemic insecticide. They get absorbed into the plant tissue and when the pests bite into them they get a mouthful of poison.

Will that cause any issues with shoot development?

No, these insecticides are formulated to not interfere with the plants internal processes. Just follow the instructions on the packaging. Scale not only suck the nutrients out of the plant but they break through the protective layer on the leaf and let other organisms in, like bacteria and fungus. Always best to get rid of them.

I would take time and go over everything with a fine tooth comb. If you miss just one or two then they're back in no time. There has been damage on citrus but haven't seen any on mango.

I did pick them off but I’m not sure if there are any tiny ones on the branches

Maybe touching them with a swab dipped in rubbing alcohol would work.

Tropicbreezent would a systemic insecticide be safe to use in a pot?

You can get sprays or pellets/tablets. The pellets usually include fertiliser to promote uptake. They're designed to be used in pots. You always need to read the information that comes with the product. They're supposed to have a safety data sheet which just about covers everything. If the safety data sheet is missing off the product ask the retailer for one. You can also get them off the internet. They're sometimes called a Material Safety Data Sheet (MSDS) or just Safety Data Sheet (SDS). Read them before you buy so that you're well informed.

I've never used them on potted plants but don't believe there'd be any greater issues than you'd get with inground plants. I used a spray one on an Abiu for Mealy Bugs that ants were bringing in. Eventually got rid of the ants as well so there wouldn't be any reoccurrence. Used the pellets on a Ficus tree with Thrips but the tree was far too large and it wasn't very effective. A potted tree is small so you're bound to get results.

Use a Copper Fungicide