[SR-Users] Dynamic rtimer interval, transaction to replace in-memory dispatcher list

Hello, I have two slightly related questions, and would appreciate any advice on the matter. The first one is about dynamic `rtimer` (or `timer`) intervals. In the route, called by the timer process there is a request to a neighbor service. In the response there's a set of new destinations for in-memory dispatcher list and some TTL value. And I need to adjust the timer interval based on this TTL (e.g., timer interval may be 10 min, but TTL may suggest to request destinations every 5 min since now). Also, the first call to the timer route should be at T+0, not at T+interval. As far as I can tell from `rtimer` module implementation, that's unfeasible. But maybe I'm missing something? Any suggestion on how one should implement something like this? The second one is about updating in-memory dispatcher list. After receiving and parsing new destinations in the timer route, the previous in-memory destinations must be replaced by these new destinations. The naive way of doing so would look something like: `dispatcher.reload` to clear previous list, then a series of `dispatcher.add` calls to add new destinations. But a failed `add` call may lead to wrong in-memory destinations set. As far as I understand I should start using some transaction-aware database for dispatcher destinations, and literally write a transaction. Are there any other ways to solve this?