If you test positive you will most likely be moved to a different facility as you will require ongoing treatment and monitoring and unless your SHA+ hotel can cater for this, you will find yourself sent to the so-called "covid jail"!
If your Dubai trip is not essential I would seriously reconsider right now. Flying there is not such a big problem, but returning is a headache. You will either have to spend seven days in a hotel room quarantine, or (better option) spend seven days in one of the sandbox options (Phuket, Krabi etc). The big danger is if you test positive on your return you could find yourself banged into hospital quarantine. Be aware
Raece Grindrod. Most immigration offices will issue the 30 day extension before issuing a covid extension, so the OP might be limited to only 60 days if the covid concession is not extended further
Ken Chao. There's been a number of reports, and the 3 million has been introduced for OA visas obtained from embassies. For extensions it will be introduced in September this year.
Lyndon Cunningham. The point I was making is that Phuket Sandbox is not quarantine. However, with the increase of positive tests I wouldn't be risking a short trip. In fact, I'd probably even be waiting a bit longer if it was an extended trip. Sandbox loses its appeal if you're going to end up in quarantine anyway.
Manuel Miele. You would need power of attorney citing the reasons why the applicant cannot attend. Contact the relevant immigration office to see if there's anything else they would need
If you do not extend before expiry you will most certainly be fined 500 baht per day overstay. There are no exceptions. You may have to engage a friend or an agent to do it for you. Keep in mind going onto overstay gives immigration every reason to refuse further extensions as you've already signed a declaration stating you accept this condition