Can I extend my 45-day visa exemption in Thailand after visiting Cambodia?

HI ALL

I m now in Laos

I stay few day to visit vientiane city

And back to thailand

On visa exemption 45 days

If I go for exemple ti phon penn by flight 26 march to 30 march

My question

Can I have an other 45 days exemption ?

(Because my flight return ti my home country (France is 8 May)

Should I take proof of exit flight when I come to thailand this Sunday?

Thank you for your answer

If I