I'm not familiar with the Octatrack capabilities. When it comes to sample playback and looping, the majority of in-rack sampling modules do not offer time compression/expansion of samples.
So if you have a drum beat at 120BPM and want to use it in your 125BPM session then you're probably going to have to take it to some software like Ableton to get it to time expand correctly. A lot of Eurorack modules support slicing. But that might make your loop feel janky.
It probably would be a lot cheaper to keep her. If the Octatrack supports sequencing as well, then you might find a MIDI to Eurorack interface and a line to Eurorack level converter (for audio) to be more to your liking. Depending on your interface you could also convert MIDI CC to Eurorack CV and MIDI clock to Eurorack clocks (short gates). MIDI to Eurorack interfaces come in a broad range of capabilities. They can be brutally simple to having a boatload of features and outputs.
But if you want to keep everything in the rack (your decision) then one of the above mentioned Eurorack solutions would work albeit not as well as stand-alone sampler workstation.