Something I would change is the way brainstorm deals with tissue names when imported from SimNIBS4. In in_tess_simnibs.m, line 60 and below, the function assigns some default names to the tissues, but this won't work with exceptions such as including an extra tissue, or for instance having the lesion instead of "electrodes".
case 'SIMNIBS4'
% Relabel the electrodes and gel
MeshMat.Tissue(MeshMat.Tissue==100) = 11;
MeshMat.Tissue(MeshMat.Tissue==500) = 12;
% Default tissue labels (from file: final_tissues_LUT.txt)
MeshMat.TissueLabels = {'white', 'gray', 'csf', 'skull', 'scalp', 'eyes', 'compact', 'spongy', 'blood', 'muscle', 'electrode', 'gel'}; % I WOULD CHANGE THIS