Follow your instincts , that is your workflow. Do what is more convenient, think about playing rather then getting lost in theory.
We are talking guitar amps here, not 0 to 200 kHz. Use S/P-dif if it is convenient for your setup. I routinely switch between digital and analogue and the difference is small. This is from someone that on the other side of the job takes these small things into account, each and every one of them....
You can go into Logic without worrying too much as long as you avoid clipping and then gain staging if you need lower levels. If I am not mistaken Logic is 32 float, not sure about the newest release so really no worries once you are in the digital domain. You may want to avoid clipping on the way out generally speaking as lesser converters can have problems reconstructing a clipped signal.