OK, here's a version with tap tempo and relative smoothed time control.
Note that you have to tap to get it started since the initial delay time is 0. The relative time control uses the proportional time modulation input for a range that corresponds to the delay line length.
Note that these patches use the factory 1 pole LPF for the smoothing - one might want one that goes lower in frequency than 8Hz for even more smoothing at the cost of the fastest rate that the delay time can be changed.
It may be possible to make a writer that uses a portion of a referenced table, but that is a rather specialized functionality (which may require a matching reader), and I think that other means of making room should be tried first.
Edit: added tape flutter to the delay just to keep myself entertained...
seq_test_1_smooth.axp (22.8 KB)