Remote config for (mobile?) apps

Many mobile apps this days use Firebase Remote Config for feature configs, feature flags, A/B tests etc. I'm not any different then of rest of developers - I'm using it too. It's free and simple to use but has some limitations and downsides:

• you still need to use Firebase SDK (no so lightweight) even if you want just this feature
• you can only use simple key - value configs (without nesting)
• you can't use arrays

So I was thinking that I could create service which would allow you to:

• have nested configs
• support for arrays
• config variants (for A/B tests)
• configs per projects
• possibility to update your config using dashboard or REST API
• fetch your config by REST API (no need for any SDK, you decide if you cache your config and when you fetch it)

This of course don't have to be limited for mobile apps - anything could use that by simply fetching config however they want.

Do you think this could be used and people would willingly switch from Firebase? And if people would pay for that (free plan for small apps and subscription plans for bigger projects)?