A transaction (or maybe transaction handle would be the better term) is available from reevaluation and admission tickets. That is, everywhere during a transaction, you can read reactives, but also create them. The reading values is core to any reactive propagation. But creating reactives using the Initializer is a liability to the scheduler, but a superpower to the operators. Its a classical tradeoff, but it would be better to not make this choice by default, that is, reactive creation should be limited such that we can experiment with schedulers that do not have this liability.