Build one H5P activity tied to a specific learning objective. Ask a few learners to complete it on desktop and mobile, including keyboard-only navigation where possible. Check whether feedback explains mistakes and whether the result reported to your learning platform matches what the learner actually did.
Interactive content can look engaging while teaching little. Keep an accessible alternative for learners who cannot use the activity, and export a copy before relying on a host integration. Use observed learning and maintainability as the comparison criteria.