MS SQL 2017 cluster: impact of disabling distributed transactions for an availability group

A company is having a Microsoft SQL Server 2017 Enterprise cluster (RTM-GDR, 64-bit, 14.0.2027.2, KB4505224) consisting of one Availability Group (AG) with two servers, a primary and a secondary. A closed source application used by this company seems to work fine with the exception of one piece of functionality. When this functionality is used, the following error can be found in its log file:

Cannot use SAVE TRANSACTION within a distributed transaction

A possible workaround, according to an unrelated website, is to disable distributed transactions by:

ALTER AVAILABILITY GROUP MyaAG
   SET ( DTC_SUPPORT = NONE );

After testing, this seems to solve the issue. However, I am uncertain about the impact of this change. - What impact does this change have? - Is the cluster still active? - Is the data still replicated to the secondary server? - Does it have a positive or negative impact on the performance? - Has a safety feature just been disabled?