If all your databases are in SIMPLE recovery model, you should not care about log truncation. With this model, space is automatically reclaim from the transaction log when checkpoints occurs (when datas are written to disks). Nevertheless if your .ldf is growing too big, you still have the possibility to use the DBCC SHRINKFILE command in order to reduce his size.
You should take care about log truncation when you database is in FULL recovery model. the Microsoft doc says : "Under the full recovery model or bulk-logged recovery model, the inactive part of the log cannot be truncated until all its log records have been captured in a log backup. This is needed to maintain the log chain "
Here an example of the "log chain" from severals inheritance backups :
Note the first_lsn and last_lsn values. The log chain is consistent