Yes. However, good luck re-entering after you exit - as TfL pretend that the Elizabeth line core is part of the Underground (it's not) and that break of journey is thus prohibited.
The above seems to apply even when you wish to break a journey which inherently requires changing to TfL from National Rail at Farringdon - as I would sometimes like to do when travelling on tickets like Radlett<->Reading.
Past aggravation from trying to do the equivalent (Circle/H&C/Met rather than Elizabeth, but same difference) at Moorgate when travelling on the likes of a Hertford<->Reading deters me from trying - even as a sometime member of the politely awkward squad when provoked.
I'm not sure anyone even knows definitively what the position technically is under those circumstances. All the current version (02/22) of the NRCoT says on the matter is:
16.4 Tickets valid for travel across London using Transport for London services do not entitle you to break your journey on London Underground and/or the Docklands Light Railway, unless your Ticket is a Season Ticket or a travelcard covering the Zones in which you are travelling.
This doesn't apply because I've not yet commenced my journey via TfL services and am at a station at which the relevant National Rail services arrive and have a gateline to the outside world by definition. It seems to be a complete lottery how the staff on the ground deal with it. It varies between cheerily waving you through and obdurate hostility, seemingly at random.