Could there be something similar in Harrison?

Otherwise you could take a look at ZL Splitter: https://zl-audio.github.io/plugins/zlsplitter/installation/

There is also the Hyperion EQ from Joachip: https://robotplanet.dk/audio_plugins/hyperion_eq/

Don't know if it's Mastering-ready.

I use this, but mostly for sidechain:

Robbert van der Helm Releases FREE Spectral Compressor

Developer Robbert van der Helm has released Spectral Compressor, a FREE compressor for Windows and Mac. I’ll readily admit that I have too many compressors, as I’m sure everyone does at this point. Despite the plethora of dynamics processors in my plugin folder, there is always room for one more. Spectral Compressor is something familiar

Bedroom Producers Blog (bedroomproducersblog.com)

Harrison's Spectral Compressor has been the only native alternative suitable for mastering I have found so far.

With the things I have produced already I can easily say, that there will be no difference in quality at all. But I will be able to use an older laptop to get the same results though

There is plugins where I have a hard time finding good alternatives for more specialised tasks (Soothe 2 fx), but right now all of the most crucial ones work through Yabridge. So even that argument (missing plugins) doesn’t always hold up.

Letting the functionality shape my creativity. If you see a person who is deep into the ins and outs of a DAW, I think it’s quite clear that the DAW becomes an instrument of its own.

I’m trained in live music and only a little in produced music, and the difference is becoming more and more clear to me. So this is also about the musician I am and how my ideas comes out.

Ableton: The editing workflow for audio events, with the edit window in the lower screen. Makes it so fast and intuitive to pitch, stretch, change algorithm, pitch automation and more. Bitwig can do the same - but it takes more clicks and getting used to new short cuts.

Studio One: Tools for traditional songwriting, song sections, chord track, lyrics etc…

Turns out I really like Bitwig for mixing, the mixer page is intuitive and easy.

Do you miss anything from Studio One? I have tested the Linux beta but without DDP support, it is not as usable for mastering for now. Still cool that they are testing the waters though!

Right now it makes me slower, which doesn't really matter since I'm not in a hurry while in between projects, but eventually I will find a new workflow and new ways of working.

On Mac OS I have been used to switching between Studio One for songwriting/mixing and Ableton for sound design/electronic musicproduction. When I found out Studio One still wasn't stable on Linux, I started to test Bitwig for all purposes, which is actually working out fine.

Yes, I‘ve learned that every setup is very personal, even within the same line of work.
And ever changing at that. I hoped this might be insightful into the mindset associated with mastering music. Where do you put your focus concerning functions?

Part 3 is not incorporating commercial plugins as of yet, maybe a Mastodon post about that is in order

Looking much forward to Part 3 and to hearing more about what paid plugins you have started using (if anything new).