I use to check hot download on new classes i create because it's relation with switchover (if hot download causes no issue, I expect switchover not causing issues.
Anyway, hot download is strongly dependant on configuration "style". As rule of thumb, wired based logic will support hot download but coded logic not (Calc/Act based logic)
Do not expect SFC/EQM to support hot download properly because sequence will not "emerge" where it was. Reentrant SFC design is required to, manually, be in position to rerun and put it where it was
Enviado: Monday, August 18, 2014 07:27 PM
Para: DeltaV@community.emerson.com <DeltaV@community.emerson.com>
Asunto: RE: [EE365 DeltaV Track] Download Procedure in DeltaV
From Books On Line article 'Downloading Data':
www3.emersonprocess.com/.../c_download_data.html
"A download temporarily disrupts the part of the operation of the controller or workstation that is being downloaded. Care must be taken to determine if the process can withstand this temporary disruption. To ensure the safety of the process, it might be necessary to delay the download of the configuration changes until the process can be shut down. To minimize the effects of such disruption, it is recommended that only those parts of the configuration that have changed be downloaded. This is particularly important in the case of controllers."
This article and sub-articles provide a very thorough description of how specific downloads affect the system.
In general, you should expect a download to be disruptive to the system being downloaded and then any systems that have dependency on that system.
There are design principles that can be employed to mitigate cascaded disruption, but it must be planned well in advance.