Why?
Newer isn't necessarily better.
You mentioned the r-07.
The r-05 is better. Been using the same unit since 2011 and it has never failed me.
Anyways, you do you. I guess we all have our preferences.
Nothing wrong with the r05, from what I’ve heard I wouldn’t think it’s inferior to the r 07.
If newer was always better I would already found a solution and wouldn’t have asked for advice here.
However old electronics fail, even my M10, which was in excellent condition, developed a strange spike at around 20kHz, I couldn’t hear it of course, but something failed somewhere.
So I’d rather minimize risks where I can…