If an Amish person were to get a body modification(s) during their Rumspringa period, would they be permitted to come back to their community at the end of Rumspringa?

If an Amish person were to get a body modification, such as a tattoo, during their Rumspringa period, it could potentially be an issue if they decide to return to the community. The acceptance of modifications depend on the specific Amish group's rules and the discretion of the church leaders. In many cases, visible body modifications might be frowned upon, and the individual might be asked to remove or conceal them before being fully accepted back into the community.
Ultimately, the decision would be made by the church leaders and the community.

This issue is discussed in the book "Rumspringa: To Be or Not to Be Amish" by Tom Shachtman. The book explores the Rumspringa period and gives an insight into how different Amish communities deal with the transition back to church life, including the possible consequences of behaviours such as body modification.

In more conservative Amish groups, body modification can make it difficult or impossible to rejoin the church. The individual may be asked to remove the modification (e.g., closing piercings or attempting to cover or remove tattoos) before being considered for readmission and baptism. Some more liberal Amish groups may be more lenient, especially if the person expresses sincere regret and a willingness to abide by the "Ordnung" in the future.

https://www.goodreads.com/book/show/385664.Rumspringa