It’s been a few years since I tried Hootsuite, but when I did, yes, IG penalized posts posted by 3rd party apps. They want you USING the platform. It’s how they make money. If you can reap all the benefits without being on the platform itself, it doesn’t do IG/FB much good.

This may have changed, but I’d be surprised if they made it easier to use the platform without actually using it.

Try some test posts though and use your analytics to see if you get less views when posting via a 3rd party.