Your PC is way more than enough for 480p content, even if it was 10bit.
Basically you could "max out" SVP's settings and still not even get close to hitting the limit of your system.
Really then you might as well just set everything to maximum (except artifact masking) and then experiment with the following two settings because they will directly effect the artifacting:
SVP Shader
Motion vectors grid
(though for anime, you don't really want to use any shader settings other than "Sharp" or "Complicated")
Also, with such high settings, you may need to increase the amount of processing threads that SVP uses (currently it's "automatic" selection is not great) because otherwise you can get slow performance while still only using like 30% CPU utilization; you want to use the smallest amount of processing threads possible that still gives you a perfectly smooth result.
A couple other things to recommend that are not exclusive to anime nor SVP but can still help:
If you use MadVR, set SVP to use your Intel integrated graphics while your Radeon 390 is used for MadVR.
Also use MPC-HC's or MadVR's automatic resolution changer (may require the use of custom resolutions) to automatically set your screen refresh rate to an exact multiple of the source video frame rate (because 24fps playing back at 72Hz is smoother and has less artifacts than 24fps playing at 75Hz).