For those who aren't happy with the existing preamp, have you thought about the NE1 preamp pedal?
Gives you the chance to emulate Mr East without having to touch the innards of your bass.
There's one on ebay currently for £60 IIRC
Available on many Chinese and/or sites IIANM. 🤥
https://www.ebay.co.uk/itm/325706558229?hash=item4bd59fab15:g:-rwAAOSwtk9kkqag&amdata=enc%3AAQAIAAAAwIA7KRszsFD38vnX6SLLIp286GVJiKx7m13ifC2upbL5M7TiSdH9M3Ulh1FnX0y9RKz7vEX%2BS7v2FlXBwcMfffnUNF2Dv8cou47X3yppNnPNOc%2BpAI4GRwUgD5ozJ1YOh9xOBrhX%2FwZtXZBl1msTFwM5tXHXTQuR2Z0wo8KPFi8KjJN3Zgj%2BGZclLiWkaGI%2FDyvPSc%2Bu%2F2T3X5FnuAj7cymDkE98h1GQznJHOQvmqoUE27mvcOEqAPLCZcqRST1VNQ%3D%3D|tkp%3ABk9SR5CR0ICfYg
I keep seeing red ones for sale but rarely any black ones. I purchased a short scale Ray instead when one came up in all white.
The mini Squiers seem to be very desirable for very little IMO.