Making sure you're not showing them by nsfw content, etc. or your advertisers will pull out.
I can't think of a single service that provides ads for 3rd party clients to use.
Most are hostile to 3rd party clients due to threatened ad revenue, that's why there's invidious, nitter, etc. whackamole.
Which you can control by just returning the ads as part of the API response for the feed, which I'm sure how the official client does it. Making the client classify NSFW content and hide ads based on that seems like a stupid idea.
At the very best the rouge app won't display ads.
At the worse, they'll ignore a nsfw tag and won't show the spoiler overlay, angering your advertiser.
Audits can catch it, but only after the damage is done.
I don't think there's any service that lets their ad supported plan be in the hands of a 3rd party client.
I was mainly asking has it been done by any service?
Risking your advertisers is not wise and audits will be expensive and reactive not proactive.
But for nonrecurring expenses, Twitter was profitable before Musk’s buyout both torpedoed ad revenue (when it was announced, before it was even completed) and saddled it with massive expenses to finance the buyout.
The acquisition is literally the only reason it is any concern how long Twitter can operate at a loss.
I always assumed the third party clients just provided a better interface. I didn't realize they circumvented the income stream.
If the third party clients were removing the means of monetization, for a company who struggles to profit, then it seems obvious that requiring paid access on its way, regardless of the owner. Twitter can't go forever at a loss.
The "surprise" is surprising.