Overstay while another Visa is pending

Hi all,

I am a NZ citizen on a Tier 5 Visa due to expire 26th September, I have been offered a job in Ireland and am working on the application for a Trusted Partner Critical Skills Visa with my employer. They hope this will take process (4-6 weeks) however there could be a chance that it will be (8-12 weeks) if they don’t meet the trusted partner criteria from the Irish government.

In the ideal world the first option will succeed and I can get my Irish Visa in time before my UK Visa expires, but does anyone have any advice or experience for the latter situation where a visa for another country is pending and you have overstayed your time here in the UK?

I believe you have to send your passport away as part of the Irish Visa application, but I plan to request for this to be sent back to me ASAP, so it is with me if I do need to exit the country.
Is there a possibility if I have my passport for me to go out of the UK and come back in as a tourist while this is processing?

If anyone can offer advice that would be really appreciated.

I would advise against leaving and trying to come back in as a visitor; there is a risk you would be denied entry because you'd be here to work in Ireland without the right visa for that.