BTP sub accounts set up

[S0017638240]

Issue description

Hi
Once we set up VTP subaccounts - should we create a separate sub account for 3 types of testing, i.e. instead of the usual DEV, QAS and PRD, should I create 5 tier structure of DEV, QAS-SIT1, QAS-SIT2 , QAS-UAT and PRD?
The reason is coming from the on-premise S4HANA team, which created 5 instances of the S4HANA, while we developed on BTP 4 apps with SAP Clean core approach using SAPUI5 and CAP side by side hybrid .
Is it any method to have just one QAS sub account in BTP, but connect to 3 different S4HANA Systems simultaneously?
I assume the Directory is the object highest than subaccount, so if the Space could be connected in Destinations to different S4HANA on the premise instances (i.e. in the Cloud Connector).
Also if we will use 5 tier account, I wonder how will we set the users IAS, IPS, CPI connections with the third party solutions and Work Zone Sites ?
Does it make since to go for 5 sub accounts? How could we govern the transport of the solution across the solution?
This is not clear from your documentation template mentioned here https://help.sap.com/docs/btp/btp-admin-guide/setting-up-your-account-model and would be nice to get SAP Best practices for the same. In the checklist there is no mention of the need to split testing phases in SIT1, SIT2 and UAT due to the fact that BTP is more Agile oriented that the on-prem S4HANA, but in the hybrid model, the Enterprise still stick to the Waterfall methodology, while has been trying to run some of the developments in SIT1, SIT2 and UAT in parallel.

For example - do we need to make 5 tiers for this architecture for Work Zone and deployed to it on Cloud Foundry applications?

Looking forward for your kind prompt response,

[email protected]

Feedback Type (Optional)

clarity

Page Title on SAP Help Portal (prefilled)

SAP BTP Administrator's Guide

Page URL on SAP Help Portal (prefilled)

https://help.sap.com/docs/btp/btp-admin-guide/setting-up-your-account-model