Adding Short TTL data on a customer profile to allow use in Email or DM

I need advice on AEP/AJO users best practices in AEP regarding profile and profile size. We have been working under the basis of always keeping the AEP Profile as light as possible.

There are times when we need to send communications to customer that require several custom attributes that become impractical to send via a triggered event AND especially when these will need to be exported for print (AJO does not export attributes that are not enabled to profile as you know)

Challenges:

• Sending all attributes in a triggered event schema becomes challenging, as the event needs to be manually triggered outside AJO
• Sending all attributes via an event does not work for DM process in AJO, which only exported data on profile

Possible Solution

• Would it be possible to add these as a specific custom communication schema enabled to profile with a very strict and short TTL?

Scenarios:

• Need to send a payment letter to a X thousand customer per month and it has 15 attributes in the letter for personalization that are not currently on the Customer Profile and specific to only that letter
• Solution:
• From connected source, batch send the custom attributes to the schema, setting a TTL for 3months for this data set
• Marketing team trigger the journey to the customer (Read Segment or Event) to the Print Vendor, allow the custom attributes to be exported
• Data will be removed from the adobe customer profile within 3 months, returning it to stand profile size

Questions:

• Have you done this? Is this advisable?
• Is there a cap on the number of attributes that can be on a profile in total that you have run into?