Dango looks like a promising mix Gloop!!!
Is it okay with you if I add some thoughts???
If not just tell me to F off (please), I won't be offended, at all.
here's what I would do.........
Add a second cream to compliment FLV Cream. Doing so will add more creaminess and mouthfeel without detracting from the fruit profile. FLV Cream is a fairly neutral cream flavor. I use it a lot because of that, but I always add another cream for better definition.
FLV Cream 1% and WF Vanilla Cream Extra 1% or SSA Clotted Cream 1% would do the trick. Bonus, adding a second cream will kill the dryness you experienced.
Yeah, Jackfruit is "one of those" that truly needs to be SFT'ed. IRL, it has a rather unique flavor. I would drop it altogether from the mix.
I would strongly suggest buying a real Jackfruit and a Mango, doing so will help your mixing. Same goes for other fruits. IMHO.
I agree with Fran, lower the grapefruit to bring the mango profile forward.
Or sub SSA Grapefruit or FA Grapefruit for FW Ruby Red Grapefruit. Those are more realistic and less harsh.
Alternatively, lose FLV Mango and go with FLV Ripe Mango and FLV Sweet Mango at low %'s (like 1.5% and 0.75%). Keep Island Mango as is. Island Mango really needs the help of another mango for a more complete mango profile (IMHO). It's not good enough to stand on it's own (IMHO).
If you want the grapefruit/mango blend to really "POP", then add 0.25% SSA Natural Lemon. It will boost the overall fruit profile without adding any lemon flavor. Think of it as a blending agent. If doing a 10ml mix, 1 drop SSA NL will do the trick.
Add a bakery flavor, for some texture and complexity. Something like, FW White Cake 3% and CAP Cake Batter 0.5%. The cake batter will add noticeable moistness to the mix. FW Cake Batter Dip, same %, does the same thing.
Add FLV Sweetness or CAP Super Sweet, 1 drop per/10ml to pull the mix together. It won't add any sickly sweetness to the mix, just helps to tie everything in the mix together.
Just my 2 cents........ I never go by the average usage ranges on ELR, ATF or FB for recommended flavor percentages. Unless, I know the mixer, and more importantly, how they go about developing their recipes. As I said, just my

...... so, take it with a grain of salt.
Good luck with however you decide to proceed!!!