How to overcome the static public IP limitation for Azure Application Gateway

The Azure Application Gateway does not allow associating a static public IP. However, this is a very painful limitation, since the DNS record should only use a CNAME, and that a CNAME cannot be defined for a root domain (see RFC1034) or it can be the only record for the domain. Which means: no mail sever for the domain, no TXT record, ...

This has crazy side effects: let's say I'd like to use the 'App Service Certificate' and get an SSL cert from Azure... The verification step requires me to define a new TXT record. Which I can't... Other situation: if I want to setup a mail server on this domain: I can't! Because no MX record can be configured on the same domain than the CNAME.

Clearly, a static public IP would allow to define an 'A' DNS record, and overcome all those limitations. However, should one wants to use a static IP, Azure recommends using a Load Balancer, which:
a) is not able to perform the Path-based rules I need from the Application Gateway
b) cannot even be set in front of the Application Gateway

So I'm wondering which kind of best practice is suggested when it comes to using an Application Gateway in production.

Hint: I will not (and cannot, anyway) prefix my webiste domain with 'www' as a workaround.