@Geodesy Editing of simple features should not cause any issues.
Refer to Client and geodatabase compatibility
Per this compatibility matrix, you should keep the geodatabase (SDE) at version 10.8.1.x to remain compatible with both ArcMap 10.8.1 and ArcGIS Pro 2.6. Note that ArcGIS Enterprise 10.9.1 is the last (most compatible) version with ArcMap 10.8.2 (last release). Starting at ArcGIS 11.0, many ArcMap dependent features are deprecated.
Removal of ArcMap-based runtime from ArcGIS Enterprise
Also, note that the compatibility matrix suggests staying at ArcGIS Pro 2.9 (if continuing to use ArcMap). I have seen users, editing with compatible version of ArcGIS Pro (say Pro 2.9); they may use later version for read-only functions, analysis, search, query (say Pro 3.1). You will quickly realize being in unsupported/incompatible versions for Desktop (ArcMap and Pro), Enterprise and Geodatabase. It becomes a huge issue for IT/GIS admins to maintain a mixed environment with limitations on upgrades, service packs, security patches. You may continue to operate mixed desktop apps, as long as there are no issues. But this not a best practice and does not align with ArcGIS implementation architecture patterns.
There are many enhancements in ArcGIS including geodatabase objects created by ArcGIS Pro. Solutions like ArcGIS Utility Network, Trace Network, Parcel Fabric, Pipeline Referencing are developed for ArcGIS Pro and comprise of GDB objects that can only be read by ArcGIS Pro. GDB functions like Attribute Rules, Contingent Values are specific to ArcGIS Pro.
@DanPatterson cited the lifecycle link that states ArcMap is in extended support and will be retired March 2026. There are many resources to start/plan Migration to ArcGIS Pro:
ArcGIS Pro migration guide
Migrate from ArcMap to ArcGIS Pro
Ayan Palit | Principal Consultant Esri