Ableton Live Tutorial
How to Preserve Macro Assignments when Replacing Multi-Sample Simpler Instruments Grouped to an Instrument Rack
This workflow tutorial video demonstrates a couple of ways that you can replace a Simpler Instrument grouped to an Instrument Rack, and do it in a way that allows you to retain the Macro assignments. This can be a real time saver for quickly building drum kits or a group of instrument presets requiring consistent Macro control.
Here's a synopsis of what's in the video with some additional info:
Title Bar vs. Sample Display
Dropping a new Simpler Instrument onto either the Title Bar or the Sample Display of an existing Simpler Instrument, will update the Simpler Instrument with the new sounds yet preserve the Macro assignments. However, you will get a different result depending on which one of the two places you drop the new Simpler Instrument.
Title Bar
Dropping the new Simpler Instrument over the Title Bar, will preserve the Macro assignments, but the entire Simpler Instrument will be replaced, with the parameter settings of the new Simpler Instrument overwriting the settings of the existing one. This is similar to using Live's Hot Swap feature.
Sample Display
By contrast, dropping the new Simpler Instrument over the Sample Display will only replace the samples and their associated mappings, leaving all other parameter settings intact.

Pictured above is a Simpler Instrument grouped to an Instrument Rack, complete with Macro assignments. The green dots indicate which parameters are assigned to Macros.

Notice that instead of displaying a waveform, the Sample Display says Multisample Mode. That's because this Simpler Instrument started it's life as a Sampler Instrument, to accommodate 8 multi-velocity sample zones, along with a few additional parameter settings that can only be accessed from within Sampler.

You should also take note that the Low Cut Macro is controlling Simpler's Cutoff Frequency, which is set to a 24dB High Pass Filter. I want these settings, along with any of the settings that were made from within Sampler, to remain consistent for all of the drum sounds in the kit I'm building, so I'll need to choose the Sample Display area, to drop the new Simpler Instrument. The only extra steps I'll need to make are to rename each new Simpler Instrument and it's associated Instrument Rack.

Now, if instead of dropping the new Simpler Instrument over the Sample Display, I drop it over the Title Bar, the Macro assignments will remain, but the settings of the existing Simpler Instrument will be completely overwritten. This could be the way to go for swapping out instruments that will require the same Macro controls, but with different parameter settings, such as their filter type. An advantage to dropping the new Simpler onto the Title Bar is that the name of the instrument is updated, although you'll still want to update the name of the Instrument Rack.