tmm,

Welcome to the BIAB forum. I think you could accomplish this by inserting two separate measures in the place of this one measure. The first would be a two beat "triplet" measure with tempo adjusted as you did before. The second inserted measure would be regular two beat measure (back at initial tempo). The score for this would look all wrong, but it should play all right.

Bruce


Macbook Pro 2018
2.6 GHz 6-core Intel Core i7, 16 GB RAM
OS Monterey
BIAB for Mac 2022