Hi @JoostU, Great questions!
Yes, we definitely expect to explore alternative warheads in coming rounds of synthesis. Actually, quite a lot of acrylamides have been ordered as a part of Ugi hit expansions such as here https://covid.postera.ai/covid/submissions/adc59df6-a3dd-4d89-ae76-550f19fbfbe3 Last I checked, the feeling is that those hits may still be mostly K_{inact} driven, and some tuning needs to be done.
And I expect that is the feeling with many of the hits showing lower IC50 too.
As for past inhibitors, quite a few are being made! If memory serves, I believe we have at least 6 synthetic chemists on past inhibitors for the next two weeks. There is a lot of interest in getting them into structures as soon as we can. And I have also put through orders for the Real Space compounds you so kindly helped me look into here A brief exploration of past SARS small-molecule inhibitors