Slow mission loading times (about 5 minutes) when moving from Cetus / Fortuna Relay to associated Free Roam mission (Scarlet Spear event concern)

[(XBOX)cubeof11]

My account is experiencing slow loading times (about 5 minutes long) when transitioning from a Cetus or Fortuna Relay to its associated Free Roam mission (Plains of Eidolon or Orb Vallis) by using the in-Relay gates or elevator.  This delay is not present when using the Star Chart in Navigation to visit those Free Roam destinations directly from the Orbiter or a Relay.  I am concerned that the Flotillas in the upcoming Scarlet Spear event might depend on the same technology and want to nominate my account contents for testing to ensure that operation is enjoyable.

• I'm playing on an Xbox One X console (with Warframe installed on external storage).
• Loading using Navigation from the Orbiter or a Relay to a typical Star Chart mission (such as Isos, Eris) as a host or client takes about 20 seconds.
• Loading using Navigation from the Orbiter or a Relay to a Free Roam mission (such as Orb Vallis) as a host or client takes about 30 seconds.
• Transitioning from Fortuna to Orb Vallis using the elevator (or from Cetus to the Plains of Eidolon using the gates) takes about 5 minutes regardless of whether I'm taking a bounty or not.
• For comparison, another newer Tenno that plays Warframe infrequently on the same Internet connection but on an original Xbox One console (installed on internal storage) moves from Fortuna to Orb Vallis in under a minute.  This is why I think this behavior is account-specific.
• This extended loading time has been present for about 6 to 12 months and wasn't present on the initial launch of Cetus or Fortuna.
• Selecting 'Board Railjack' using the menu from the Orbiter takes about 40 seconds to enter the Railjack.  (This is provided as an example of in-mission loading times.)
• Loading the next zone in Elite Sanctuary Onslaught ("Opening Conduit..." message) takes about 7 seconds.  (This is provided as an example of in-mission loading times.)

Some theories on the source of the extended loading time:

• At one point about 4 months ago, I noticed that if I stayed in Fortuna or Cetus for several minutes (for example, if I was early and waiting for night for the Eidolon hunting bounties to appear) prior to transitioning, the delay was significantly shortened to about half, but I haven't been able to reliably replicate this.  I speculated that maybe the game was busy loading the fashion of other Tenno in Cetus or Fortuna and needed to let those queued downloads drain out first even if I've left the Relay already.
• I have a large number of unclaimed items in the Foundry (429 as of this writing).
• I have a large number of Sentinels (about 44 according to the Featured Stats in Warframe's Game Hub / Official Club on Xbox Live, but those statistics haven't been updating for several months --- I've increased my Mastery Rank twice and it isn't reflected in the corresponding statistic, but that is a topic for another bug report).
• I have a large number of digital purchases on Xbox Live (about 400 games installed on Xbox One) and probably around 1,000 items in My Library in the Microsoft Store across all product types.  I mention this because I saw a line item in Update Notes several years ago where logging in to Warframe was sped up for accounts that had a large number of non-Warframe purchases.
• It has probably been resolved now, but I previously had an in-game inbox containing thousands of messages that once resulted in the inbox user interface soft-locking on login (support desk ticket number 1264696) --- maybe you can reference any internal notes for that case for additional insights of areas in my account that might stress the system.

This behavior was observed in the Xbox One edition of Warframe, title screen version 2020.03.11.12.08.

Edited April 2, 2020 by (XB1)cubeof11
Additional sample in-mission loading times and the client version number are added.