According to DxOMark, even many native FE Sony / Zeiss lenses have poor resolution on A7R body (especially FE 50/1.8 and some zooms) or have some problems with distortion and aberrations (e.g. FE 28/2). Even the new Sony FE 35/1.8 have some troubles on A7RIV. In general, the best results with A7RIV will be from Sony GM prime lenses, Zeiss Batis and so on and - I think - APO-M 50, 75, 90, 135.
I use APO 75 & APO 90 on A7RIII (42 MP without Kolari MOD) - both leness are super sharp, any aberrations etc. Focusing is easy thanks to magnification and focus peaking in EVF. M-lenses wider than 50mm for me are unacceptable on A7RIII body.
I think that APO 50 - 75 - 90 - 135 are superb also on 61MP's A7RIV (I planned to buy one after real users reviews appears).