Eligibility for PS & Safe Harbor 401(k) Contribution is Year of Service, dual entry
Eligibility & Entry for 401(k) Deferrals is immeidate

Plan is Top Heavy

Any way to avoid providing TH minimum and/or Gateway minimum to Participants only eligible to make deferrals? Can we somehow disaggregate the Plan?

If Top Heavy 3% is unavoidable, anyone buy the argument that the Gateway minimum is 5% of 0 for the otherwise excludable employees, because we exclude pre-entry compensation for the Employer Contributions?

TH is unavoidable. If you disaggregate the otherwise excludable employees for nondiscrimiation testing and you don't test the otherwise excludables on a benefits basis, then you don't have to provide the gateway minimum. Your suggestion to exclude compensation is not viable.