Are all 3rd party software/applications bannable?

Are you talking about a man in the middle attack or a VPN?

Remember there are people who promise they have an optimizer that  improves your latency and input lag, all of these are shady and I would not touch them with a firepole. VPN if its pure VPN should not do anything since some isps still use vpn as firstmile connection from their customers, I also know several is using this also against Apex Legends, its not supposed to be a violation, but I cant guarantee still, that needs an official answer.

Edit: Just wanted to stop you doing a wataheck desision. A bud just got his pc hacked because of this, an optimizer for lower latency for Apex, and then they jailed his pc for money, and deleted his servers from discord and he is still not certain what the full fallout is. If it was me I would not do that, but ofc its all up to you when the time of decision comes 😉

There is more than 1 software, there is razer cortex and special k.