In the actual announcement of the production increase of 7 March...

In the actual announcement of the production increase of 7 March PPK does not provide timing of the expansion to 10 kilograms per week. However, on a chart in the 4 May market update presentation, it shows this production volume in H2 2022. It is not clear if 10 kilograms per week is achieved by end June and is therefore the average over H2 2022, or if it is achieved sometime during H2 2022 (and therefore the half year average would be less). In reading the chart it looks to me like it could be the average, and that 10 kilograms per week could be achieved around mid 2022.

If something is "brewing" - i.e., presumably putting in place the big production increase ahead of contracts with already known large customer(s) - then that should become visible reasonably soon.

It really is hard to know the nature of the potential customers referred to. It is pure speculation but my best guess is the US defence industry, which has the money, the technical sophistication and requirements, and given events around the world is doing very well. Global defence is given much prominence in a pie chart by PPK in the 4 May presentation.