Tidal orbital decay is suspected to occur for hot Jupiters in particular, with the only observationally confirmed case of this being WASP-12 b. By examining this effect, information on the properties of the host star can be obtained using the so-called stellar modified tidal quality factor Q?’, which describes the efficiency of the planetary kinetic energy dissipation within the star. In this study, we aim to improve constraints on the tidal decay of the KELT-9, KELT-16, and WASP-4 systems, making it possible to constrain the Q?’ value for each star. In addition, we aim to test the existence of the TTVs in the HD 97658 system, which previously favoured a quadratic trend with increasing orbital period. Making use of newly acquired photometric observations from CHEOPS and TESS, combined with archival data, we fit three models to the data, namely a constant-period model, an orbital-decay model, and an apsidal-precession model. We find that the KELT-9 system is best described by an apsidal-precession model for now, with an orbital decay trend at over 2?? being a possibility as well. A Keplerian orbit model provides the best fit to the transit timings of KELT-16 b because of the scatter and scale of their error bars. The WASP-4 system is best represented by an orbital decay model at a 5?? significance, although apsidal precession cannot be ruled out. For HD 97658 b, we find no conclusive evidence for the suspected trend in the data.