Yes, there you need to use TARCER.
The following returns 0:
$LoadTARCER = True; $LoadFeynArts = $LoadPhi = False;
$FeynCalcStartupMessages = False;
Needs["HighEnergyPhysics`FeynCalc`"];
tst1 = FeynAmpDenominator[PropagatorDenominator[Momentum[l, D],
Sqrt[mf^2]], PropagatorDenominator[Momentum[l, D], Sqrt[mf^2]],
PropagatorDenominator[Momentum[l, D], Sqrt[mf^2]]]*
(mf^3*Pair[LorentzIndex[mu, D], LorentzIndex[nu, D]] +
4*mf*Pair[LorentzIndex[mu, D], Momentum[l, D]]*
Pair[LorentzIndex[nu, D], Momentum[l, D]] -
mf*Pair[LorentzIndex[mu, D], LorentzIndex[nu, D]]*
Pair[Momentum[l, D], Momentum[l, D]]);
TarcerRecurse[ToFI[OneLoopSimplify[tst1, l], {l}, {0}]]
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