Legacy Form use in Mobile Application

Hi Champions,

Need your help for mentioned scenario, 

We have an application with 230+ rules with legacy form for desktop version. Now, we want to use the same application in mobile version. But we are facing challenges with complex rules that are not functional in mobile app. which was working fine in desktop. some of the challenges as below:

1. After inserting the data and saving the form, but without values form getting saved Including mandatory fields are saving as blank in table.
2. Popup messages are appearing in form after filling every field. which supposed to popup only once, if it meets the rule condition. 
3. HTML coded error messages are not appearing on form in mob. 
4. sometimes while saving the form unnecessary rules are getting triggered.  and so on.....

Alternatively, we planned to use a modern form but, modern forms are limited to 100 rules only and to use the modern form into Forms dropdown for Mobile section modern form is not appearing. QB support team says feature still in 'Beta'.

Can someone please help here to achieve the goal. Did any of you faced the similar challenge? or you know any solution, please suggest. 

Thank you.