...plus, you can combine techniques. A palm-slap is common with thumb-slap, but could be used with finger-style as well. I did that decades ago. Double-thumbing is sort-of like pick-playing, with the sharp attack only on the 2nd half of a double-thumb (finger-nail): the first half of the double-thumb sounds like a cross between thumb-slap and plucking with index or middle. Palm-muted pick-playing on rounds can be funky if you play stacatto and have some growl in your tone.
The bass is sort-of hidden in the mix on this song anyway. You got this!
Seems like if you get that percussive funk feel that's what's needed. I'll work on what you've suggested. Thanks.