Currently a Slash 2.0 doesn't provide enough. It's warm but there's no chug.
A 59/Custom was straight up harsh and much much worse...
What options do I have before I sell the guitar...
I've deleted my previous answer in this topic since I had not read your initial post above attentively and was recommending a 59/Custom.
At first glance, I don't see how a 59/Custom could be "straight up harsh": its stronger coil closer to the neck should give more bass and its inductance is 1.5 times higher than with a P.A.F. clone, focusing the sound in the high mids...
I start to wonder if it's not this focus in the high mids that your rig and ears translate as "thin" sounding. It would explain what happened with the Gibson AY which is supposedly nothing else than a 57 Classic + with an A2 bar.
Anyway: I've shared a few solutions based on external components (parallel resistors and/or capacitors) in your other topic on the AY. Fellow members have evoked higher gain humbuckers whose twice higher inductance should effectively give enough chug.
Now and for the record, a trick to try with any 4-conductors humbucker is to wire it "inside-out": swap the start and finish of each coil. It will change the electrical relationship between coils while keeping the humbucking process and in some cases, the related comb filtering helps to match the resonance of a moody guitar.
Below is the raw electrically induced response on a linear scale of a 4-cond. humbucker normally wired then connected "inside-out', as an example. Standard wiring has more high freq content than "inside-out" wiring in a range that a guitar amp and cab still translates as "presence"... I think (not sure) that the pickup involved was a 59/Custom, precisely.
