I'm not really sure why you would buy a scope to do what is essential mixing/MASTERING.

I should have given more context. That's not what I'm doing.

The scope is mostly used for looking at DC/modulation signals. When I'm trying to finesse a modulation signal with an attenuation and offset, for example. Or when I get new modulation modules, helping me understand exactly what they are doing so I can figure out how to use them best. It's for testing signal flows within my patch when things aren't working as expected.

I guess I approach patching like software programming and the CV scope is my debugger. Although I sometimes mindlessly experiment, I often have a specific idea that I'm trying to pursue and sometimes I need to see what's going on to make it happen. To give a specific example: One thing I like doing lately is feeding an LFO into a waveshaper and then into a clock-triggered quantizer. It's really helpful to see what's going on there while looking for the "sweet spots".

Asking about external scope options comes from the fact that I have a Zeroscope 1U and it is very useful to me for these purposes, but I only use it when I need it which is not most patches, so I want to swap it out for more "day to day" utilities.

I know the correct solution here is to get a bigger/second case and keep using the Zeroscope, but I was wondering if there's an affordable external option that could be useful for other purposes, such as in DIY contexts. I was also just curious how you connect a modular system to a general-purpose scope. It wasn't obvious. Thanks for pointing me to https://www.threetom.com/product/threetom-wiretap/

I like this suggestion:

personally I'd go for a expert sleepers interface (which I have) and use one of the scopes in vcvrack

If I can get a DC signal into my computer then I can do whatever I want with it. It probably makes more sense for me than buying dedicated hardware. I'm not sure I'm equipped to do that at the moment, but I'm going to keep this option in mind.