I gather that the SRG1119E is no longer valid from 13th Jan 2022 (Ref sky wise.caa.co.uk SW2021/295).
It's replaced with SRG3108 which the applicant fills in online. I revalidated (by experience + 1 hour instructional flight) an SEP rating today for a PPL holder and watched whilst the applicant completed the 3108. It was very straightforward, doesn't require any signatures and provided a licence reissue is not required, free. You can keep a copy of the form (download it, or have one emailed to you) for your records when you've submitted it.
I think you would be able to complete one of these in addition to the 1119E that you have just sent in without anything getting complicated.