Definitely a good way to feel out the bass EQ, yeah.
This becomes a much bigger difference when you start putting effects between the bass and the amp. That’s when the distinction I mentioned becomes important - the EQ on the bass sets the bass tone, which then goes through whatever effects you are using and is modified. Then it goes in to the amp, which is no longer EQing just the bass, but also the tone added by all the effects. At this point the controls are quite different in effect, because you have placed the preamps at different places in the signal chain.
I’m at the opposite end of the scale. I don’t use an amp at all, and always record clean bass and apply all EQ, effects, and amp sims in the DAW. But that’s because all I care about is recording and not playing live.
Goofing around with the knobs is real fun.
I made a little sheet to, hopefully, help get you started on trying out different combinations and listening for differences in what the two different pieces - bass and amp - can do with each other.
This is NOT by any means a reference or bible or rule for how to set things up. It’s just some beginning suggestions.
The take away is (as has been nicely covered by these rad other folks here):
The bass can change the most, and can change song to song.
The amp is something you adjust - hopefully once - per situation (gig/rehearsal) to set it for the best possible sound to accommodate the music and the room, and to get your sound and volume to work with the rest of the instruments and environment.
Bass adjustments might be drastic - things all the way up or down depending on the song or the vibe - amp adjustments are usually moderate - between 9 o clock and 3 o clock on the dial, and usually hovering around 12.
Try some of these out, and see if you connect to the controls and the different things they do to the sound.
So tone up = more treble leaning
Tone down = more bass leaning
Mids = will need some experimenting. Hi/low mids etc. start with them flat and play with them after you are comfy with bass and treble.
I don’t really mess with them much unless I want slap or super dark boomy.
Generally I find mids are the most important to be able to tweak. I usually either want to boost or cut them, depending on what I am playing. I won’t buy another 2-band EQ, I’ve owned three and always wanted a mids control on them.