With an iPad/iPhone and an Analog Heat, you could host a compressor on the iDevice (or any number of EQs, multi-band compressors etc.) and use the soundcard built-in to the Heat to get Compression => Heat.
I was just about to muck around with this today using my iPad Pro. I used my iPhone 11 Pro in the past to test this and it worked really well. If you want to use the Fabfilter stuff though you need an iPad. No iPhone versions.
Only caveat is using lookahead will introduce some latency so be mindful of that.
Edit: @micabeza recommended this software to test RTL in iOS. I just hadn’t setup the test conditions for it.