The superior luminosity of CEBAF, high resolutions of detectors, and ability for multidimensional and multiparticle detection, makes the Jefferson Lab unique in disentangling the genuine intrinsic transverse structure of hadrons encoded in 3D partonic distributions, including Transverse Momentum Distributions (TMDs) and Generalized Parton Distributions (GPDs) in the kinematics dominated by valence quarks. Measurements of multiplicities and asymmetries of multiparticle final states in wide kinematics, including dihadrons and vector mesons, will be crucial for a separation of different structure functions, and different dynamical contributions to specific structure functions, used in phenomenological studies of Semi-Inclusive DIS (SIDIS). Recent studies of exclusive vector measons performed at JLab indicate understanding of the impact of exclusive vector mesons is absolutely critical for interpretation of SIDIS, and will be even more relevant for measurements performed or planed at higher energies. A new analysis framework has been proposed, called "rho-free SIDIS", allowing separation of contributions from exclusive vector mesons from inclusive pion SIDIS.
Precision measurements at JLab, including detailed studies of the $Q^2$ dependences of observables, would also allow testing the impact of several theoretical assumptions used in phenomenological studies of generalized PDFs (GPDs, TMDs) , also providing a mechanism for validation of extraction frameworks, which is critical for proper evaluation of systematic uncertainties.