The main product for the company that I am working is an ad server. So many sprints are tech and back end focused with small tweaks to the UI. The design iterations are so slow that it may take months for a user to notice slight changes on the dashboard of the product.
Another issue that our users are publishers and advertisers (ad ops) with specific knowledge about ad servers, so it is almost impossible to use user testing platforms as our user's tech skills are very specific and also very hard to get them on board to run user tests.
Few of my colleagues proposed to do user tests for the entire journey by adding additional tasks to the user tests. I feel like this is very painful as the journey is very long and what we want to test are small style updates and features.
What your suggestions ? How often should I run user tests ?